Leviticus 19:17

Thou shalt not hate thy brother in thine heart
Although no hatred may be expressed either by words or deeds, yet being in the heart is a breach of the sixth command, see ( Matthew 5:21 Matthew 5:22 ) ; and of this a man may be guilty, when he does not attempt to save the life of his neighbour, either by bearing a testimony for him, or by delivering from danger, as preserving him from drowning, from wild beasts and thieves, as in ( Leviticus 19:16 ) ; or when he does not reprove him for sin, as in the next clause, but suffers him to go on in it to his ruin, either of which by interpretation is an hatred of him: thou shalt in any wise rebuke thy neighbour,
for any sin committed by him, though secretly, yet known; which rebuke should be private, and repeated as may be found necessary, and given gently in meekness and tenderness: and not suffer sin upon him;
unconvinced of, unrepented of and persisted in, which may prove of fatal consequence to him; and therefore to let him alone, and go on in it without telling him of it, and reproving him for it, would be so far from acting the kind and friendly part, and showing him love and respect, that it would be an evidence of hating him at heart, at least it might be strongly suspected: or, "and not bear sin for him" ^F1; become a partner with him in his sin, and so become liable to bear punishment for it; which is a strong reason for reproving sin, in a proper manner, lest we should be partakers of other men's sins; see ( 1 Timothy 5:20 1 Timothy 5:22 ) .