Gemara

"You will eradicate the innocent blood from your midst" equates all murderers to Eglah Arufah. Just like the calf is killed by the neck, also murderers.

Question: We should also learn that we use a chopper and cut from the back of the neck!

Answer (Rav Nachman): "V'Ohavta l'Re'acha Kamocha (love your fellow man like yourself)" - choose a nice death for him (so he will die quickly).

Shabbos 31a: A Nochri came in front of Hillel and requested conversion on condition to be taught the entire Torah while standing on one foot.

Hillel: Do not do to your friend what is hateful to you. The rest is commentary. Go learn!

Pesachim 113b (Rav Shmuel bar Yitzchak): One may hate a person (for transgressing Ervah).

Question: "Ki Sir'eh Chamor Sona'acha Rovetz..." refers to a Yisrael. One may not hate a (proper) Yisrael - "Lo Sisna Es Achicha bi'Lvavecha"!

Answer #1: The case is, witnesses testified that he transgressed.

Rejection: If so, he would not be called "Sona'acha" - everyone hates him!

Answer #2: The case is, you alone saw him transgress Ervah.

(Rav Nachman bar Yitzchak): It is a Mitzvah to hate such a person - "Yir'as Hash-m Senos Ra."

Nedarim 65b (Mishnah - R. Meir): (If one vowed not to get benefit from another), we may Pose'ach (prompt him to regret it) by telling him what the Torah says;

We say: 'You are transgressing "Do not take vengeance and "Do not bear a grudge" and "Do not hate your brother in your heart" and " V'Ohavta l'Re'acha Kamocha."

Sanhedrin 84b - Question: May a son let blood from his father?

Answer (Rav Masnah): "V'Ohavta l'Re'acha Kamocha" (since the father wants, it is permitted).

Kidushin 41a (Rav Yehudah): It is forbidden to Mekadesh a woman without seeing her. Perhaps he will not like her appearance, and he will despise her, and transgress "V'Ohavta l'Re'acha Kamocha"

Nidah 17a (Rav Chisda): It is forbidden to have relations during the day -- "V'Ohavta l'Re'acha Kamocha."

Question: How do we learn this from the verse?

Answer (Abaye): Perhaps he will see something repulsive in her, and he will despise her.

Rishonim

Rif and Rosh (Eruvin 33b and 10:13): It is forbidden to have relations during the day due to "V'Ohavta l'Re'acha Kamocha."

Rif and Rosh (Nedarim 22 and 9:3): We may Pose'ach by saying 'you are transgressing..."V'Ohavta l'Re'acha Kamocha."

Rif and Rosh (Kidushin 16a and 2:1): It is forbidden to Mekadesh a woman without seeing her. Perhaps he will not like her appearance, and he will despise her, and transgress "v'Ohavta l'Re'acha Kamocha"!

Rambam (Hilchos Ishus 3:19): It is not fitting for a man to Mekadesh a woman until he sees that she is pleasing to him, for if she is not he will divorce her or cohabit with her even though he hates her.

Rambam (Hilchos De'os 6:3): It is a Mitzvah for every person to love every Yisrael like himself. Therefore he must speak laudably about him, and be concerned for his money like he is concerned for his own money and honor.

Aruch ha'Shulchan (OC 156:7): One is not commanded to divide his money with others. V'Ohavta l'Re'acha Kamocha was not taught amidst monetary laws, rather, amidst the Isurim of talebearing, hatred, vengeance and bearing a grudge. This teaches that the Mitzvah is not to do evil to another, and (to benefit others in) things in which there is no loss of money.

Rambam (Hilchos Evel 14:1): It is a Mitzvas Aseh mid'Rabanan to visit the sick, console mourners, take out a Mes (for burial), bring a Kalah (to Chupah), to escort guests, and engage in all needs of burial, and to rejoice a Chasan and Kalah. These are Chasadim with one's body. They are unlimited. Even though all these Mitzvos are mid'Rabanan, they are included in v'Ohavta l'Re'acha Kamocha. Whatever you want others to do for you, you should do them for your brother in Torah and Mitzvos.

Rambam (Hilchos Mamrim 5:7): L'Chatchilah one should not remove a thorn or let blood from his parent, due to the Isur to wound him. If there is no one else to do so and the parent is in pain, the child does whatever his parent permits.

Poskim

Shulchan Aruch (YD 241:3): A son should not remove a thorn or let blood from his father, due to the Isur to wound him.

Rema: If there is no one else to do so and the father is in pain, he does whatever his father permits.

Beis Yosef (DH u'Mah she'Chosav Lefichach): Rav Masna answered v'Ohavta l'Re'acha Kamocha, i.e. one is commanded not to do to others only what he does not want done to himself.

Shulchan Aruch (252:2): One who neglects redeeming captives transgresses...and "V'Ohavta l'Re'acha Kamocha".

Shulchan Aruch (EH 21:3): It is permitted to look at a single woman, whether or not she is a virgin, to see if she is pretty and he wants to marry her. Further, it is proper to do so.

Beis Yosef (DH u'Mutar): We learn from Kidushin 41a.

Shulchan Aruch (EH 35:1): It is forbidden to be Mekadesh a woman through a Shali'ach if he could do so himself, unless he already recognizes her. We are concerned lest he see something displeasing and she will be repulsive to him.

Beis Shmuel (1): Nowadays, we make Shiduchin and the Chasan does not see the Kalah, because he will see her before the Kidushin.

Shulchan Aruch (ibid.): It is forbidden to Mekadesh a woman without seeing her. Perhaps he will not like her appearance, and he will despise her, and transgress "v'Ohavta l'Re'acha Kamocha"!

Magen Avraham (OC 156:2): It is a Mitzvas Aseh to love everyone in Yisrael like himself, like it says "v'Ohavta l'Re'acha Kamocha". This refers to your companion in Torah and Mitzvos. It is a Mitzvah to hate a Rasha who does not accept rebuke.

Pischei Teshuvah (YD 240:14): If a father tells his son 'do not say Kaddish for your mother', he should not obey, for the father transgresses "v'Ohavta l'Re'acha Kamocha."

Pischei Teshuvah (244:4): If a Chacham knows how to play instruments, may he play for a Chasan and Kalah, or is this a disgrace to the honor of his Torah? Chavos Ya'ir (205) says that the Rambam and Rosh argue about this. The Rosh says that a Zaken v'Ein l'Fi Kevodo (a Chacham who encounters a Mitzvah such as loading an animal or returning a lost object that it is undignified to carry) may not be stringent to do the Mitzvah. The same applies here. The Chavos Ya'ir retracted and said that here all permit. All know that he is not paid and does it solely for the Mitzvah l'Shem Shamayim. The Rosh discusses Mitzvas Aseh Bein Adam l'Chavero in which the Torah exempts one who would not load or carry such an Aveidah if it was his own. We are commanded v'Ohavta l'Re'acha Kamocha (like yourself). If one is stringent, it looks like an unjustified disgrace of his Torah for the sake of his money. There is no disgrace regarding a Mitzvah Bein Adam la'Makom, and all the more so, a Mitzvah sheha'Zman Grama. It is praiseworthy to belittle oneself for Hash-m's concerns, even if it is not truly a Mitzvas Aseh, merely Chesed which we learn from "V'Holachta bi'Drachav".

Kitzur Shulchan Aruch (25:13): "V'Ohavta l'Re'acha Kamocha Ani Hash-m" - you must love your fellow man like yourself because I created him.

Aruch ha'Shulchan (OC 215:1): One who hears a Mi she'Beirach (after an Aliyah l'Torah) should answer Amen, to fulfill v'Ohavta l'Re'acha Kamocha.

Rema (CM 272:10): The Mitzvah to help a Sonei load does not have precedence over helping a friend unload if the Sonei transgressed. In such a case he need not load with him to overcome his Yetzer. It is proper to hate him!