Rebuke, Revenge, and Love

Rashi on Leviticus 19:17
ולא תשא עליו חטא [THOU REBUKE THY COMPANION] AND NOT BEAR A SIN ON ACCOUNT OF HIM — though rebuking him thou shalt not expose him to shame (lit., make his face grow pale) in public, in which case you will bear sin on account of him (cf. Sifra, Kedoshim, Chapter 4 8; Arakhin 16b).

Sefer HaChinukh 240:1
To not whiten the face: To not embarrass an Israelite; and our Rabbis, called this sin (Avot 3:15), "whitening the face of his fellow in public." And the negative commandment that comes about this [in the Torah] is that which is written (Leviticus 19:17), "you shall surely rebuke your compatriot, and you shall not bear a sin for him." And they said in Sifra, Kedoshim 4:8, "From where [do we know] that if you rebuked him four or five times [...] go back and rebuke [him again]? [Hence] we learn to say, 'you shall surely rebuke.' Perhaps, he should rebuke and his face change [color]? [Hence] we learn to say, 'and you shall not bear a sin for him.'"

Chizkuni: לא תשנא את אחיך בלבבך, “do not hate your brother (fellow Jew) in your heart.” If it has come to your attention that someone made negative comments about you, accused you falsely behind your back of wrongdoing, do not bottle your resentment up in your heart by hating him.” You should rather הוכח תוכיח את עמיתך, “remonstrate with your colleague about having wrongly accused you,” asking him what prompted him to badmouth you. Perhaps, once matters are in the open you can demonstrate to your colleague that he completely misinterpreted one of your actions. Alternately, you will become aware that what had been reported to you as having said by him about you was misrepresented, and not meant detrimentally at all. (B’chor Shor) You are to act in this manner even if you are convinced that your remonstrations will not help at all. In fact, your failure to make an attempt at reconciliation will be held against you by the heavenly tribunal. This is why the verse concludes with the words: ולא תשא עליו חטא, “so that you will not burden him with a sin.”

Rashi: לא תקם THOU SHALT NOT AVENGE — If one says to another “Lend me your sickle", and he replies, “No!", and the next day he (the latter) says to him (the former), “Lend me your hatchet”, and he retorts, “I am not going to lend it to you, just as you refused to lend me your sickle״ — this is avenging. And what is “bearing a grudge”? If one says to another, “Lend me your hatchet”, and he replies “No!” and on the next day he says to him “Lend me your sickle”, and he replies: “Here it is; I am not like you, because you would not lend me” — this is called “bearing a grudge (נטירה)” because he retains (נוטר) enmity in his heart although he does not actually avenge himself (Sifra, Kedoshim, Chapter 4 10-11; Yoma 23a).

Rashbam on Leviticus 19:18:
ולא תטר; not even in your heart, but train yourself to resist your natural impulse to get even.

Rambam (AKA Maimonides) on 19:18: It is a commandment to all people to love each and every Jewish person as themselves, as it is written: "Love your neighbor as yourself" therefore people should say good things about others, and to be careful about others' money just as they would be careful about their own money, and desire honor for themselves.

SFORNO on 19:18 There follows a general, all inclusive rule to be observed in relations towards one’s fellow, phrased as ואהבת לרעך כמוך, telling us to apply the same yardstick to our concern for our fellow that we would want applied to ourselves if we were in his shoes in similar situations.

Tur HaAroch, Leviticus 19:17:
ולא תשא עליו חטא, “so that you will not bear a sin on account of him.” If your fellow sins because you did not call his error to his attention, you will share in his sin. Not only this, but the Torah adds that you are obligated to love your fellow man.” (Verse 18) Personally, I believe that the correct interpretation of our verse, i.e. the words הוכח תוכיח את עמיתך, is similar to when Avraham remonstrated with Avimelech. (Genesis 21,25) . .. When such rebuke is administered with discretion it may often result in resolving a dispute. Having advised us not to bear grudges without first having voiced our grievances, the Torah also instructs us not to harbour feelings of revenge for injustices real or unproven. Having taught us not to entertain negative feelings against our fellows, the Torah proceeds to demand that we relate positively to them, i.e ואהבת לרעך כמוך. You will note that the Torah does not write רעך, but לרעך. Had the Torah written the word רעך, it would have meant that we are instructed to love our fellow man’s body, his person as much as our own, an impossible task. As it is, the Torah demands that we relate to our fellowman’s possessions with the same degree of concern as we do to our own possessions. You should be as concerned for the welfare of your fellowman as for your own.