1)

(a)The reason that, by Shigegas Shabbos, one is only Chayav one Chatas for each Shabbos (irrespective of how many Melachos he performed) is - because in fact, he only contravened one Shogeg, whereas by Shigegas Melachos, he contravened as many Shegagos as the Melachos he performed.

(b)The reason cannot be because, by the former, he withdraws from the Melachah at the mention of Shabbos, whereas by the latter, he withdraws at the mention of the Melachos - because, even if, in the former case, he withdraws at the mention of Shabbos, that is only because of the Melachos which are forbidden on Shabbos, and if, in the latter case, he withdraws at the mention of the Melachos, that is only because of Shabbos, which is the source of the forbidden Melachos.

2)

(a)Shmuel learns Chiluk Melachos (that one is Chayav a Korban for each individual Melachah) from the Pasuk "Mechalelehah Mos Yumas" - which must be speaking about Shogeg (seeing as the Pasuk "Kol ha'Oseh Bo Melachah, Yumas" is obviously speaking be'Meizid). In that case - it is coming to teach us that a person can be Chayav many 'Misos' for one desecration (Chiluk Melachos).

(b)Despite the fact that "Mechalelehah Mos Yumas" is referring to Shogeg, the Torah used the Lashon "Mos Yumas" -because it is referring, not to physical death, but to monetary obligations (since, if one considers money as part of oneself, having to give away money is like killing a little bit of oneself). And here, the transgressor is obligated to buy one Chatas for each Melachah that he transgresses.

3)

(a)The thirty-nine Melachos are hinted in "Eileh ha'Devarim" at the beginning of Vayakhel - inasmuch as "Eileh" has the numerical value of 36; plus "Devarim", which means '2 things)', plus 1 more, that one adds because of the 'Hey' in "ha'Devarim"; a total of 39.

(b)Rebbi Nasan learns Chiluk Melachos from the Pasuk "Lo Seva'aru Esh" - because, seeing as lighting a fire (which was performed in the Mishkan), is one of the thirty-nine Melachos, why did the Torah need to specifically insert it, if not to teach us that one is Chayav a Chatas just for lighting a fire. And, based on one of the thirteen principles of Rebbi Yishmael (and on the fact that lighting a fire is already included in the principle Pasuk of "Lo Sa'asu Kol Melachah") now that lighting a fire has been singled out for the Din of Chatas, it comes to indicate that the same will apply to all of the other Melachos included in the principle Pasuk.

(c)Initially, Rebbi Nasan attempts to learn Chiluk Melachos from the Pasuk "be'Charish u'va'Katzir Tishbos". He rejects this as a source however - on the grounds that "Charish" and "Katzir" would then be serve as two sources, and we have a principle 'Sh'nei Kesuvim ha'Ba'im ke'Echad, Ein Melamdin' (whenever two sources teach us the same thing, they become exceptions, and we learn the exact opposite from them). (Besides, they are not good sources for our Din, since they constitute Mitzvos Asei, and Chata'os are always based on a La'av. Consequently, Rebbi Nasan learns something completely different from there - see Rashi, DH 'Talmud Lomar').

(d)Shmuel declines to learn Chiluk Melachos from "Lo Seva'aru Esh", (like Rebbi Nasan) - because he holds like Rebbi Yossi, in whose opinion the Pasuk mentions 'Hav'arah' independently, to teach us that lighting a fire on Shabbos is only a La'av, and not a Chiyuv Kares.

4)

(a)Rebbi Yossi Darshens ...

1. ... from the 'Mem' of "me'Achas" - that one will be Chayav on Shabbos, even if he does not complete the Melachah that he set out to perform (e.g. if someone set out to write Shimon, but only wrote the 'Shin' and the 'Mem', he is Chayav a Chatas, since he has written the word 'Shem').

2. ... and from the 'Mem' of "me'Heinah" he learns - that one is also Chayav for contravening the Toldos, as well as the Avos Melachos.

(b)By ...

1. ... 'Achas she'Hi Heinah', Rebbi Yossi means - that although he only transgressed once, he is Chayav many Chata'os) 'be' Zadon Shabbos ve'Shigegas Melachos';

2. ... 'Heinah she'Hi Achas' he means - that he is Chayav only one Chatas, although he transgressed many times) - 'be'Shigegas Shabbos, ve'Zadon Melachos'.

(c)Shmuel declines to learn Chiluk Melachos from the same source as Rebbi Yossi - because he does not agree with the D'rashah of 'Achas she'Hi Heinah' and 'Heinah she'Hi Achas' (although it is not at first clear how Shmuel, an Amora, can argue with a Tana - See Tosfos DH 'Lo').

5)

(a)When Rava asks 'He'elam Zeh va'Zeh be'Yado, Mahu', he means to ask - what the Din will be in a case of 'Shagag ba'Zeh u'va'Zeh'(Shigegas Shabbos and Shigegas Melachos). Do we go after the Shigegas Shabbos, and he is only Chayav one Chatas, or after the Shigegas Melachos, and he will be Chayav for each Melachah that he transgresses that Shabbos.

(b)This is not already established by our Mishnah: 'ha'Shochei'ach Ikar Shabbos, Eino Chayav Ela Chatas Achas' (incorporating both Shigegas Shabbos and Shigegas Melachos) - because there, where he forgot the concept of Shabbos, it is truly only one Shegagah, whereas in our case, there are two independent types of Shegagah, one, a Shigegas Melachos , the other, a Shigegas Shabbos.

(c)We cannot guage the answer by seeing whether he withdraws due to the mention of Shabbos, or to that of Melachos - because, as we already explained, if he retracts at the mention of Shabbos, it is only because of the Melachos, and if he retracts at the mention of the Melachos, it is only because of the Isur Shabbos.

(d)'Ela Lo Shena' implies that he is only Chayav one Chatas.

6)

(a)If we establish the Chidush of the Mishnah 'Avos Melachos Arba'im Chaser Achas' by someone who transgressed all thirty-nine Melachos in one He'elam (meaning Shigegas Shabbos and Shigegas Melachos - Rava's She'eileh) - how can Rava conclude that Shigegas Shabbos and Shigegas Melachos is Chayav only one Chatas?

(b)This problem is confined to Resh Lakish, who holds that one must be a Shogeg by the La'av as well by the Ka'res - because Rebbi Yochanan will establish the Mishnah by Shagag be'Ka'res, ve'Heizid be'La'av, which, according to Rebbi Yochanan, is Chayav thirty-nine Chata'os, because it is called Zadon Shabbos. It is only according to Resh Lakish, who holds that Shagag be'La'av is required as well as Shagag be'Kares, that our Mishnah seems to be a classical case of Shigegas Shabbos and Shigegas Melachos. Yet he is Chayav thirty-nine Melachos.

(c)We conclude that a genuine case of Shigegas Shabbos and Shigegas Melachos is only Chayav one Chatas. Our Mishnah is not a genuine case of Shigegas Shabbos however, even according to Rava - because it speaks when he knew that it was Shabbos regarding the Isur of Techumin, which, according to Rebbi Akiva, is d'Oraysa.

7)

(a)'G'reirah' is - when the Korban that one brings for one transgression covers other transgressions in the way that we will now explain.

(b)According to Rava, someone who reaped and ground twice, first be'Shigegas Shabbos and Zadon Melachos, and then vice-versa, and he became aware first ...

1. ... of the first pair of Melachos (of Shigegas Shabbos) and then of the second - is obligated to bring only one Chatas (for the first set of Shigegas Shabbos), and the first Ketzirah is Gorer the second Ketzirah, and the first Techinah, the second Techinah (despite the fact that the second set is slightly different than the first).

2. ... of the Ketzirah of the second set of Melachos (Shigegas Melachos) - he is Chayav to bring two Chataos (as we will now explain).

(c)Of the four transgressions ...

1. ... the second Ketzirah is Gorer the first Ketzirah and the Techinah with it (be'Shigegeas Shabbos) ...

2. ... but not the Techinah of Shigegas Melachos, which will become Chayav when he becomes aware of it.