לֹֽא־תִשְׂנָ֥א אֶת־אָחִ֖יךָ בִּלְבָבֶ֑ךָ הוֹכֵ֤חַ תּוֹכִ֙יחַ֙ אֶת־עֲמִיתֶ֔ךָ וְלֹא־תִשָּׂ֥א עָלָ֖יו חֵֽטְא׃
你不可在心裡恨你的弟兄；你務要責備你的同胞，也不可因他而擔罪。
Rashi
ולא תשא עליו חטא [THOU SHALT IN ANY WISE REBUKE THY COMPANION] AND NOT BEAR A SIN ON ACCOUNT OF HIM — i. e. 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).
Ibn Ezra
Do not hate your brother This is the negative aspect of “love your fellowman as yourself” [:18]. Although these commandments all involve a person’s private emotions, only through their observance will Israel be permitted to remain on its land (The Second Temple was destroyed because of groundless hatred [Yoma 9b]).
Ramban
THOU SHALT NOT HATE THY BROTHER IN THY HEART. Because it is the way of those who hate a person to cover up their hatred in their hearts, just as it is said, He that hateth dissembleth with his lips, but he layeth up deceit within him,83Proverbs 26:24. therefore Scripture speaks of the usual events, [mentioning, thou shalt not hate thy brother ‘in thy heart,’ but the law forbids all hating, even if done openly]. THOU SHALT SURELY REBUKE THY NEIGHBOR, This constitutes another commandment, that we must teach him reproof of instruction.84Proverbs 6:23. For the commandment is a lamp, and the teaching is light, and reproofs of instruction are a way of life. See “The Commandments,” Vol. I, pp. 219-220. THOU SHALT NOT BEAR SIN BECAUSE OF HIM, for you will bear sin because of his transgression if you do not rebuke him. Onkelos’ rendition tends towards this explanation, for he translated, “and do not receive guilt because of him,” meaning that you should not be punished by his sin. Following these commandments He then said [in the following verse] that you are to love your neighbor. Thus he who hates his neighbor violates a negative commandment, and he who loves him, fulfills a positive commandment.
The correct interpretation appears to me to be that the expression ‘hochei’ach tochiach’ (thou shalt surely rebuke), is similar to ‘V’hochiach Avraham’ (And Abraham reproved) Abimelech.85Genesis 21:25. The verse here is thus stating: “do not hate your brother in your heart when he does something to you against your will, but instead you are to reprove him, saying, ‘Why did you do thus to me?’ and you will not bear sin because of him by covering up your hatred of him in your heart and not telling him, for when you will reprove him, he will justify himself before you [so that you will have no cause to hate him], or he will regret his action and admit his sin, and you will forgive him.” After that He admonishes [in the following verse] that you are not to take vengeance of him, nor bear a grudge in your heart against him because of what he has done to you, for it is possible that he will not hate him, but yet he will remember in his heart his neighbor’s sin against him; therefore He admonished him that he is to erase his brother’s sin and transgression against him from his heart. Following that admonition, He commanded that he love him as himself.
The correct interpretation appears to me to be that the expression ‘hochei’ach tochiach’ (thou shalt surely rebuke), is similar to ‘V’hochiach Avraham’ (And Abraham reproved) Abimelech.85Genesis 21:25. The verse here is thus stating: “do not hate your brother in your heart when he does something to you against your will, but instead you are to reprove him, saying, ‘Why did you do thus to me?’ and you will not bear sin because of him by covering up your hatred of him in your heart and not telling him, for when you will reprove him, he will justify himself before you [so that you will have no cause to hate him], or he will regret his action and admit his sin, and you will forgive him.” After that He admonishes [in the following verse] that you are not to take vengeance of him, nor bear a grudge in your heart against him because of what he has done to you, for it is possible that he will not hate him, but yet he will remember in his heart his neighbor’s sin against him; therefore He admonished him that he is to erase his brother’s sin and transgression against him from his heart. Following that admonition, He commanded that he love him as himself.