Proverbs 24:29

Say not, I will do so to him as he hath done to me
He has falsely accused and reproached me, and bore a false testimony, or suborned false witnesses against me, and I will do the same to him, now an opportunity serves; but as private revenge itself is sinful, so especially when it is pursued in a wicked way; I will render to the man according to his work;
this should be left to the Lord, whose prerogative it is; see ( Proverbs 24:19 ) ( Romans 12:19 ) .