with a select treasury of commentaries on all levels of Torah interpretation
Chapter 4 Mishna 2
with select commentaries
Abbreviations used in this translation:
RSHI - Rashi Commentary (1040-1105)
RMBM - Rambam (1135-1204)
BRTN - Rabbi Ovadiah of Bartenura Commentary (1445-1515)
TFRT - Tiferet Yisrael commentary (1782–1860)
YONA - Rabeinu Yonah (1180-1263)
MHRL - Derech Chaim - Maharal of Prague (1525-1609) (from hebrewbooks.org/14193)
VLNA - Biur HaGra of Rabbi Eliyahu of Vilna - (1720-1797)
Commentary Legend: | |
![]() | - for basic commentaries as relating to the plain meaning (Pshat). |
![]() | - elaborates more into the theme. |
![]() | - deeper in, Maharal of Prague. |
![]() | - more themes in the text. |
Chapter 4 Mishna 2פרק ד משנה ב
Ben Azzai would say: run to pursue a minor mitzvah as if it were a major mitzvah and flee from a sin. For a mitzvah drags with it another mitzvah, and a sin drags with it another sin. For the reward of a mitzvah is a mitzvah, and the reward of a sin is a sin. | בֶּן עַזַּאי אוֹמֵר, הֱוֵי רָץ לְמִצְוָה קַלָּה כְבַחֲמוּרָה, וּבוֹרֵחַ מִן הָעֲבֵרָה. שֶׁמִּצְוָה גּוֹרֶרֶת מִצְוָה, וַעֲבֵרָה גוֹרֶרֶת עֲבֵרָה. שֶׁשְּׂכַר מִצְוָה, מִצְוָה. וּשְׂכַר עֲבֵרָה, עֲבֵרָה: |
Bartenura - "For a mitzvah drags with it another mitzvah" - this is the way of the world. One who does a mitzvah desires to do more mitzvot, while one who starts with sins, it is difficult for him to stop.
"the reward of a mitzvah is a mitzvah.." - one who does a mitzva is helped and assisted from Heaven to do another one so that he receives reward for both. And likewise for the "reward" of sins, etc.
Another explanation: the reward of a mitzva is a mitzva. All that a person benefits and rejoices in doing a mitzvah, this is considered a mitzvah by itself. He will receive reward for the mitzvah he did and also for the joy and pleasure in performing it.
"the reward of a sin is a sin" - in doing a sin, the benefit and enjoyment a person attains is considered a sin by itself. He will be punished for the sin itself and also for the benefit and enjoyment he received in committing it.
Tiferet Yisrael - "run to pursue a mitzvah" - i.e. be careful to sanctify your intent that you are doing it "because thus G-d commanded, not because of this or that, etc". For mitzvot need intent and only in this way will your soul attain perfection.
"run.. and flee from sin" - for usually when one decides to do a mitzvah, the yetzer (evil inclination) works against him to test him. But in doing a sin, it is the opposite (the yetzer pushes him to do it). On this we pray "remove the satan from before us", i.e. when we want to do a mitzva, "and from behind us", in sins.
Tiferet Yisrael - "sin drags with it another sin" - for this is the way of the yetzer. At first he entices one to light sins and afterwards to severe sins.
Shevet Mussar, yado bakol - "sin drags with it another sin" - he did not say "a sin causes (gorem) another sin", but rather "a sin drags (gorer) another sin". For a thing which is big and heavy, a man cannot lift it up but instead drags it. This is like "a mouse dragged the chametz (chulda gorerato)" (Pesachim 9a), which teaches on the heaviness of the thing. Therefore, the mouse drags it.
And since a light mitzvah drags after it a weighty mitzvah, and likewise a light sin drags after it a severe sin, therefore I am commanding you "run after a light mitzvah and flee even from a light sin"..
Yismach Moshe, Vaetchanan - "sin brings to another sin" - for through the sin, the soul becomes weak and sick. It lacks the strength to guard itself from other sins which the physical presents it. If when it was healthy, it failed to stand up to it, how much more so now. Understand this.
Sforno - "run..flee" - even though sometimes the mitzvah or sin itself is among the light ones and it does not seem to warrant running or fleeing in and of itself. But nevertheless it does warrant this due to what follows them. For a mitzvah drags another mitzvah and likewise a sin drags another sin.
The reason is because the reward of a mitzvah in this world is that G-d grants the person some ability to do another one.. And likewise the reward and pleasure of a sin in this world prepares one for another sin, similar to "you will eat of his offering and betroth of his daughters and they will lure your son to idolatry" (Ex.34:5-16).
Birkat Avot (Ben Ish Chai) - "run to do a mitzvah and flee from sin" - i.e. one must run so much after a mitzvah, even a light one, as if he is fleeing away from a sin. Namely, a person who committed a sin such as stealing or an illicit relation (zenut) and people detected it and seek to catch him, he will certainly run away with all his might as fast as he can, in order to escape and not get caught. Thus you need to run to fulfill a mitzvah, even if it is light..
Daat Zekenim in name of Saba of Kelm - "sin brings more sin" - for a sin is not an independent matter. Rather, it is an illness in the soul. The soul will suffer greatly in its illness. Thus, certainly "a sin will bring more sin", since the soul is afflicted..
in the Zohar: "every mitzvah (opportunity) which comes to a man's hands - it is a special gift (doron) which the Holy One, blessed be He, sends to a man. Perhaps you will say: 'whoever comes to grab, acquires it', thus scripture says: 'how precious is Your kindness O G-d' (Tehilim 36:8)..."
From here we learn that to acquire a mitzvah is not like acquiring a lost object in the street whereby whoever comes to grab acquires it.
Rather, each and every mitzvah is a "special gift" (doron) which G-d sends to man and it is not so easy to acquire it. One must pay a very expensive price for it.
The mitzvah is owner of itself (baalim al atzma) and man needs to have many merits in order to merit that the mitzvah will want to go to him.
This is what Rabeinu Yonah wrote that when a man does a mitzvah, this mitzvah helps him to do other mitzvahs. For a man needs much help to merit to do a mitzvah..
Michtav M'Eliyahu chelek 1 - "reward of a mitzvah is a mitzvah" - for in truth there is no other reward in this world for a mitzvah. For "there is no reward in this world for a mitzvah" (Kiddushin 39b), i.e. besides the reward in this world of "a mitzvah brings another mitzvah". In truth, this itself is true reward that G-d sanctifies us with His mitzvot and draws us closer to His service. There is no other reward in this world which is true reward. For all the good and pleasure in this world is on the foundation of error and falsehood. Only the spiritual which G-d bestows on us - this is the great reward without equal.
Chasdei Avot (Ben Ish Chai) - "run for a light mitzvah" - besides the reason that a mitzvah brings another mitzvah is that the "reward of a mitzvah is a mitzvah". For even though our sages said: "there is no reward for a mitzvah in this world", but nevertheless, there is a form of reward in this world. Namely, that the Holy One, blessed be He, helps a man to have great joy in doing a mitzvah, similar to what king David said: "I rejoice in Your torah, as one who finds great treasure" (Tehilim 119:162). The ancient ones merited this very much. They experienced tremendous joy in doing the mitzvot, as the Talmud brings: "Rabbi Yirmiya sat before Rabbi Zeira and saw he was very joyful.. He said "I put on Tefilin".. "A smile did not leave his face all day".., "when the Rabbis parted with Rebbi Ami, they said to him: 'may you see your world (afterlife) in your lifetime'"
The intent was: "may you merit tremendous joy in toil in torah and doing mitzvot". For this is reward in this world which is similar to the reward in the afterlife. Thus, the reward a man has with G-d's help in performing the mitzvot is called "the reward of mitzvah in this world".
In truth, joy is a great pleasure and benefit to the body, and nevertheless, G-d considers this joy to be a great mitzvah and He grants man reward in the next world just like other mitzvot..
This is another reason why "run for a light mitzvah". Namely, even though it appears light in your eyes and you thus think its reward is small, and do not do it zealously, but it is not so. Rather, run after it to fulfill it. For the reward of a mitzvah is joy. This is the reward of a mitzvah in this world and G-d considers the joy as a mitzvah and gives reward for it in the next world just like other mitzvot.
Therefore, if a mitzvah opportunity comes to your hand, let it not be small in our eyes thinking that since the mitzvah is light, certainly its reward is small and it is not worthwhile ch'v. For every mitzvah has another mitzvah tied and bound to it. Namely, the joy which is called "the reward of a mitzvah in this world".
Thus, perhaps in this light mitzvah you will have great joy and it will be included among the mitzvot which one receives reward for. And the greater the joy increases, the greater the reward will increase.
Thus, [even] if you will receive light reward for the light mitzvah, but from the joy in the light mitzvah, you will receive great reward.
Furthermore, according to human nature, a mitzvah which is light on the body and not heavy, it necessarily has great joy, ten times more than the joy in a mitzvah which is heavy on the body.
Therefore, I told you run to a mitzvah, even if it is light. For the reward of a mitzvah is joy and it too is considered a mitzvah and one receives reward for it.
"the reward of sin is a sin" - here too, just like for joy of a mitzvah, G-d considers it a mitzvah and gives reward for it, so too in the way of bad, the reward of sin, i.e. the joy a man has in doing a sin - this itself is considered a sin. And one will be punished for it besides the punishment for the sin itself.
Siftei Daat on Avot (R.Yerucham Levovitz) - "the reward of a mitzvah is a mitzvah.." - for when one performs a mitzvah, besides the actual acquiring of a mitzvah, he receives the reward that the mitzvah elevates him to the level that he senses and detects sin and puts this to heart.
"the reward of sin is a sin" - so too for the opposite, the reward of sin is sin. For besides the actual doing of the sin, his folly dwells with him. For the segulah (special quality) of sin is that it dulls man's heart (metamtem libo) until he loses all sensitivity to sin (Daas Torah, chelek 1, pg.203).
Sfat Emet - "run.." - i.e. the running refers to the enjoyment and joy in [doing] the mitzvah.
"run to a light mitzvah" - for through the light mitzvah, he will come to do the big mitzvah and likewise by fleeing from the sins which are easy to refrain from, he will come to refrain from the sins which are difficult to refrain from.
"the reward of a mitzvah is a mitzvah" - since "one hour of torah and good deeds in this world is greater than all the life in the world to come" (Avot 4), if so, it is impossible to pay him reward in this world fully, except through "the reward of a mitzvah is a mitzvah".
Ohr Yitzchak - "run for a mitzvah.." - there is room to investigate why he used the term "run". Furthermore, he said: "a mitzvah brings another mitzvah" - but we see every man does mitzvot as soon as he wakes up in the morning such as tzitzit, berachot (blessings), prayer, and even so, he wastes the whole day idle (batel) and has no desire whatsoever for any mitzvah. On the contrary, we find many such people going after their heart's lust, falsehood, and honor.
We indeed see that sin brings more sin. But from what we see, mitzvah does not bring [more mitzvah]. Why is this so?
The truth is that if a man were to do the mitzvah with a sincere heart like he does some lust, with great fervor, clinging and longing to it with all his will and aspiration - certainly such a mitzvah would bring another mitzvah at all times.
But in truth, even when a man does a mitzvah it is without any desire and will for devekut (clinging to G-d). Due to this, the mitzvah does not have the ability to bring another mitzvah. But the sin is committed with great vitality and strength and thus it brings more sin..
This is the true service [of G-d] which Ben Azai revealed to us in saying "run to a mitzvah..", i.e. that you have at least as much pleasure and desire in doing a mitzvah as you have in secular things. Then certainly it will drag another mitzvah and the [bad] lusts will be annulled automatically. For such a mitzvah will illuminate you and open your eyes, as written: "a mitzvah is a candle and torah is light" (Mishlei 6:23). Then you will see that the lusts are reprehensible things and you will flee from sin.
Siftei Daat on Avot, Daat Chochma umussar 3:61 - "run away from sin" - in the midrash (Ber.Rabba 32:11) "sin crouches at your door (Gen.4:7)..etc: - at first it is [weak] like the silk of a spider web, and afterwards it becomes strong as the thick ropes of a ship.."
The explanation is that it is known that the yetzer hara is called "the leaven (yeast/chametz) in the dough" (Berachot 17a).
That is to say, it is the nature of the yeast that if it merely enters the dough, the dough expands and rises and rises without any other cause than the yeast itself.
So too, it is the nature of the yetzer (evil inclination) in man. For man's body is like dough so that if a little bit of the yeast of the yetzer enters in man, even a tiny amount, it will expand and rise higher and higher until eventually it pulls him like the thick ropes of the ship. Therefore, a person needs to guard himself from the beginning. This is the meaning of "run away from sin".
Siftei Daat on Avot - "run to a minor mitzvah.." - for the whole matter of man's service is in the secret of drawing closer or distancing [from G-d]. For when one does mitzvot he draws closer to G-d, while for sins it is the opposite - they distance him from G-d, blessed be He.
But we must know that the explanation is not that besides the mitzvah itself, there is an additional matter which causes one to draw closer to G-d and likewise the opposite for bad.
Rather, the secret of the matter is that the mitzvah or sin reaches the loftiest heights - the mitzvah or the sin itself is the secret of drawing closer or distancing [from G-d]. That is to say, the doing of a mitzvah itself, whether it is a light mitzvah or a big one - immediately, behold, "and G-d is with him", he cleaves to G-d absolutely. On the other hand, when doing a sin, even the slightest sin - immediately he is "with her", i.e. with the merkava of tuma itself (forces of evil). He cleaves to the evil.
In light of this certainly "run to a minor mitzvah and flee from a sin".
Yachel Yisrael - Ben Azai comes as a supplement to the words of Ben Zoma in the previous mishna: "who is mighty? He who conquers his inclination, as written: 'better one slow to anger than a mighty man, and better he who rules over his spirit than one who conquers a city'".
After a person sees the words of Ben Zoma, he may come to fall in despair and hopelessness: "how can I possibly conquer my inclination? Even king Shlomo testifies that one who rules over his spirit is mightier than one who conquers a city.
It requires more might to rule over one's yetzer than to conquer a city. I am a simple man. I have a hard time dealing with my own day to day difficulties. Can I possibly conquer a city?! If no, then how can I possibly hope to conquer my inclination?"
Ben Azai comes and says "you are not asked to get up in one single day and submit your inclination. All that is asked of you - is to do a light mitzvah. Put on tefilin, say the blessing after a meal (birkat hamazon), fix a mezuza on your door, etc."
If you fulfill the light mitzvah, already a more difficult mitzvah will follow after it. If you recite the blessing after a meal properly, you will ascend one level and already be able to pray properly.
Start with light mitzvot, simple ones familiar to everyone. Start to fulfill mitzvot even not for their own sake (shelo lishma), since "from shelo lishma you will come to lishma (its own sake, i.e. proper intent)" (Pesachim 50b)..
The service of G-d is like "a ladder fixed on the ground which reaches the heaven". It is impossible to jump straight to heaven without a ladder. One must ascend step by step. Likewise, it is impossible to ascend a ladder unless it is firmly "fixed on the ground".
Siftei Daat on Avot - Rabeinu Yonah explains:"a mitzvah brings another mitzvah" - "this is a natural power. For one habituates his nature to do a mitzvah.."Rabeinu Yonah revealed to us a great foundation. Namely, man's essence is only his free will, whether in the way of [habituating] his nature or the other way [of choosing to be with G-d].
"sin brings sin" - this too is a natural power.. for he habituates his nature to do the abominations which G-d hates.
"for the reward of a mitzvah is a mitzvah" - this is a different reason than human nature. Namely, G-d did not grant actual good and evil in man's hands, but rather free will alone to choose between the two, as written: 'you shall choose life' (Devarim 30:19).
After man chooses one path, if it is good, he goes and G-d is with him..
"the reward of sin is sin" - but if he choose death and evil.. The Holy One, blessed be He, distances from him and leaves him to his evil nature.. And then man's way is no longer [in his hands]. For he already chose this path, etc.
But after he chose his path, his way is no longer [in his hands] and he already lost his essence. Rather, from now on he is already led on this path which he chose, as our sages said: "in the path which a man WANTS to go, he is led" (Makot 10b).
For the secret of man's service is only choosing. This is what the sage said "run to do a mitzvah and flee from a sin". For the main thing is choice alone, namely, running or fleeing, "and you shall choose life"! (Daat Torah 118-119)
We learn a tremendous mussar from Rabeinu Yonah regarding just how much a man needs to put to heart and be careful in all his movements to a hair's breadth. For since nothing was given in man's hands except for free will alone, and if he COMES to purify himself, already he is helped and led on this path he chose. Likewise for the opposite, if he COMES to defile himself, the path is opened for him and already man's ways are not in his hands.
If so, it is already beyond the powers of the human mind to grasp the weightiness of each movement, even the tiniest movement of man. (Daat Chochma u'Mussar 1:22).
From the words of Rabeinu Yonah, we will understand the loftiness of the body.. For G-d seeks from man only his choice, the desire and want for the mitzvah "run (ratz) to do a mitzvah" and the "will (ratzon)" - this is all of man! For the secret of free will (bechira) is the secret of will (ratzon). And the secret of the matter of will is only inside the body. There is nothing else among all the creations in all the worlds which contains this secret of "will".
From here we learn the loftiness of the body.
I found something similar to our words in the words of the Ramchal z'l. In his introduction to "Adir b'Marom" he writes: "the first is knowing the secret of the body.. For it being alone that which causes free will. Even the soul does not have free will without it.." end quote (Daat Torah chelek 3, pg.223,228).
Translator - sometimes a person is in doubt whether what he is doing is a mitzvah or a sin. How can one know? After all, the evil inclination often disguises a sin as a mitzvah or vice versa. Besides asking a wise Rabbi, there is a litmus test - a mitzvah brings a mitzvah, while a sin brings a sin. Examine the consequences that come out of this deed. Do more mitzvot come out of this or more sins? Through this one can detect whether or not it is the yetzer hara in disguise (heard from R. Nissan Kaplan).
Sefer HaChinuch mitzvah 387 - Know my son and let it be always on your tongue what our sages, of blessed memory, said: "sin brings sin and mitzvah brings mitzvah". For if you decide to fulfill your bad lust one time, you will be drawn after it several times. And if you merit to be a "mighty man in the land", to conquer your yetzer and to close your eyes from seeing evil one time, it will be easier in your eyes to do the same several times. For lust draws the flesh like wine draws its drinker. The drunkards will never become satiated by wine. On the contrary, they will lust for it tremendoulsy. The more they habituate themselves, the more intense will be their lust for it.
If they would just drink a cup of water instead, it would weaken and extinguish the fire of lust for wine and be good for them. So too is this matter. Every person who habituates himself in lusts and is diligent in them - his yetzer will increase strength over him every day.
But when he refrains from them, he will rejoice in his portion always every day. He will see that "G-d created man upright, but they sought many considerations" (Kohelet 7:29), without any benefit whatsoever.
Matanat Avot - "a light mitzvah.. severe sin" - why by mitzvah he said: "a light mitzvah", while for sin he did not say "a light sin"? [answer:] This is to teach us how to look at mitzvot and sins. For mitzvot, one needs to have knowledge of their hierarchy, which mitzvah is light and which mitzvah is severe. This is in order to know what is more important and which mitzvot it is more worthwhile to spend time in. For if we did not know that "torah study weighs like all the mitzvot" (Peah 1), then why should a man want to spend time in torah study? He can stand in the morning at the cross roads and help children cross the street. Isn't this also a mitzvah?
But because we have an order of importance of the mitzvot, therefore, we know what we need to invest our primary life and time and what gets pushed off to second or third place.
But for sins - there is no such thing. There are no light sins for which it is ok to somehow transgress them and severe sins for which one must distance further. Rather, for all sins it is the same. For each and every one a person needs to flee from it and each one obligates a severe punishment if he does not repent.
Although certainly there are also levels in sins regarding the severity of punishment, but nevertheless, it is impossible to call it a "light sin".
For if the sage used this term, people would think there are "light sins" which one can transgress and manage with this.
The sage comes to exclude this view completely - there is no such thing (as a light sin). One must flee from every sin as one who flees from fire.
It is known that the Chazon Ish would praise Rabbi Yechezkel Levenstein saying: "by him it is clear that to commit a sin is to stick one's hand inside a fire".
For one who recognizes and feels that every sin burns and is dangerous as fire, certainly such a person will flee from every place or thing which has a concern (chashash) of sin.
Matanat Avot - "mitzvah brings a mitzvah" - why does a mitzvah bring a mitzvah and the opposite? The sage answers: "for the reward of a mitzvah is a mitzvah and the reward of a sin is a sin".
When a person does a sin, even a light one, then in Heaven they see that he wants to do the will of his Creator. Therefore, they send him assistance to do more mitzvot. Likewise for the opposite, G-d forbid.
This is like the Vilna Gaon's words in Mishlei:"in everything a person does, a ruach (spirit) is sent down from heaven , and helps him to repeat more things like these. And this spirit does not rest and quiet until the person repeats more things like this. The person then finds pleasure in doing these things, whether they are good (mitzvas) or evil (sins). And this is what is meant by 'sin brings sin and mitzva brings mitzva (Avot 4:2)'" And the greater the sin, the greater the spirit, and the greater the lust to do more evil. And likewise for a great mitzva, a spirit from a very holy place comes down and the person lusts immensely for another mitzva. And because of this, he finds enormous pleasure in doing mitzvot. As is known, the greatest of all mitzvot is learning Torah, and the opposite is idle chatter and frivolity (letzanus) which is the opposite of Torah. Therefore, there is greater pleasure in idle chatter and frivolity than in all other sins, even though there is no physical benefit, because the ruach hatuma (evil spirit) is exceedingly great....but really, the pleasure in the holy spirit is greater than the evil spirit (sin) because it is a true pleasure" - commentary on Mishlei/Proverbs 1:23In the beginning, after one act, as understood, the spirit is not so strong. But when the person is drawn after this spirit and repeats the act a second time, then certainly, the spirit intensifies. For now it is a spirit of two times. So too further on.
From here we learn tremendous mussar why it is worthwhile to run to a mitzvah and flee from sin. For in mitzvot, even though in the beginning it may require enormous effort to do, but if one strengthens himself in the beginning, afterwards, the "spirit" already pulls him and it will be much easier to do that mitzvah.
Likewise for the opposite, G-d forbid. One who starts to do some sin, even if in the beginning it is difficult and unpleasant, but afterwards, the spirit already pulls him forcefully and all the obstacles and impediments will seem straight in his eyes to commit the sin.
Maharal - "run to pursue a minor mitzvah as if it were a major mitzvah" - the explanation is that all the 613 mitzvot are one thing.. The torah is one big light.. We explained this more in its place. The torah is one and all the mitzvot are tied together until it is one complete entity. Thus, a mitzvah brings another mitzvah, i.e. doing one mitzvah is also the beginning of another since they are all one. Therefore, a mitzvah brings another mitzvah, because that which is one is completely indivisible. (see there for more)
(R. Hartman: for the spiritual is one while the physical is plural and divided.. parts apply to that which is physical, but the spiritual does not have parts.. and in Gevurot H' (ch.43), he writes: " we already expained in this book that division is a physical thing, while unity is a divine thing. For unity applies to that which is separated from the physical, while separation and division always applies in the physical".)
Chasdei Avot (Ben Ish Chai) - "sin brings sin" - for we find that the Holy One, blessed be He, made a hint to the 248 positive commandments and the 365 negative commandments in man's body (man has 248 limbs and 365 sinews). For there is one skin which joins and unites all the limbs and sinews together. This is to teach mussar to a man lest the evil inclination tempt him saying: "there are 613 mitzvot! If you lack 10 or 20 from the positive commandments and 30 or 40 from the negative commandments, this is not so recognizable".
Answer him: "the 248 positive commandments and 365 negative commandments are like 613 pearls in a necklace on a string. If a thief comes and steals two or three pearls, the owner of the necklace does not cry on these two or three that were stolen but rather on all the 613 pearls. For they are all tied together in one string. It is not possible for the thief to take one or two without breaking the whole string, and once the string is broken, all the other pearls are liable to be lost. They will slowly fall out one by one and be lost. Likewise for the 613 commandments. All of them are interconnected with each other. If a person annuls one positive commandments, he is liable to lose all of them. And if he transgresses one sin of the 365 negative commandments, even though he transgressed one sin, he is liable to transgress all of them.." This is the meaning of sin brings sin..
Chida, Zeroah Yamin - "run to pursue a minor mitzvah and flee from sin" - the word "flee" (boreach) is precise. For man is made of dust and the Sitra Achra ("other side", i.e. side of evil) clings to him. But when he is excited in a mitzvah and runs, through this he separates from the Sitra Achra and becomes as one who flees from sin, i.e. from the Sitra Achra. Thus, "run to a mitzvah", and through this you are "fleeing from sin".
Chida, Chasdei Avot - "the reward of a mitzvah is a mitzvah" - for the reward of a mitzvah is the mitzvah itself, namely, an angel of mercy is created which will defend him and serve his soul - this itself is its reward.
Likewise for sins, an angel of destruction (malach chabala) is created to punish him. The reward of the sin is the sin itself.
Maharal Tzantz - "be fleeing from sin" - he did not say "flee (berach) from sin" as a command, but rather "flee (boreach)" (lit. be fleeing). For in every mitzvah he does, he acquires extra holiness in his soul, and in this itself he distances further from sin. That which he comes closer to the side of holiness, through this itself he flees and distances from the Sitra Achra which is sin.
"sin brings sin" - for in that which he drew closer to sin, which is the Sitra Achra, he brings more sin.
"reward of mitzvah is a mitzvah" - i.e. the holiness he acquired in his soul.
"reward of sin is sin" - i.e. that which he defiles (metamei) his soul. This itself is the punishment..
Another explanation - "run to a mitzvah and flee from sin", i.e. in that which he runs to a light mitzvah he is fleeing from sin. For if he were lazy and did not run to fulfill the light mitzvah - not only does he lose the reward of the mitzvah in being lazy but further still, there is a sin in his hands in that he was able to do a mitzvah but did not do it. Thus, in running after the mitzvah itself, he is gaining the mitzvah and also fleeing from sin in not being lazy to fulfill it.
Chida, Rosh David, be'haalotcha - "sin brings sin" - for the Sitra Achra chases him and clings to him after the first sin. Afterwards, it does all sorts of strategies to make him sin and turn him and pull him like a sheep to the slaughter. In this [latter stage] he is completely unintentional. So why then is he liable? I heard from my Rav who gave a reason according to halacha. Namely, the Halacha that one is at first negligent and afterwards accidental is obligated to pay (techilato b'pshiah v'sofo b'oness chayiv).
Rabeinu the Arizal writes that what one commits in one gilgul (life) drags one to sin in the next gilgul (reincarnation) Kikar l'Eden, Derech Eretz Zuta ch.3
The primary argument the yetzer harah uses to entice man is that the pleasures of this world are recognizable and revealed and tangible to the eye. But the good of Olam Haba is hidden and concealed and ch'v "one who wants to make up a lie distances the witnesses". This is what the torah writes: "the woman saw.. that it was desirous to the eye" (Gen.2), that it is tangible to the eye. This is the whole enticement of the Sitra Achra.
Divrei Chaim tzantz, Ki Tavo - "run to a mitzvah" - every mitzvah a man does is not really an act. For everything is from G-d. Rather, the primary free choice is that which a man wants to do a mitzvah. In truth, our sages said on this: "if a man thought (resolved) to do a mitzvah but was unable to actually do it due to accident, it is considered as if he did it" (Berachot 6a). For the main thing is the will.
Our sages said in Berachot 7a: "it is a mitzvah to run after a mitzvah and after torah". The talmidei Rabeinu Yonah wrote on this: "for in this it is recognized man's desire and will. Namely, that due to love of G-d he desires in G-d's commandments and rejoices to run to do them. On this the Midrash (Devarim Rabba 7:2) says: " this is what scripture states: 'fortunate is the man who listens to me' (Mishlei 8:34), i.e. whose listening is to me. Namely, all his aspiration is to listen if there is some mitzvah in the world which he can fulfill, that he desires to hear words of torah and to do mitzvot.
This is the meaning of "[fortunate is the man who listens to me] to be diligent at my doors" (Mishlei 8:34), "doors" is written in plural, i.e. two doors, as the talmidei Rabeinu Yonah wrote (Berachot 8a). The talmud there says: "it is a mitzvah to enter inside the synagogue [at least] two door-lengths (before praying)", so that being in the synagogue does not look like a burden.
On the contrary, he should feel contentment for going to another shiur (torah class) in a faraway synagogue.
For G-d gives reward for the footsteps and this is the main reward of the mitzvot - that which he goes and runs since this hints on his longing to fulfill the mitzvah.
This is the primary reward. For the reward for the act itself is almost not in man's hands since G-d gives him strength and feet to move. Rather, the main thing is the joy and longing in the mitzvah. This is recognizable by how he walks.