1 Kings 2:8-9

8Behold, 1there is with you Shimei the son of Gera the Benjamite, of Bahurim; now it was he who cursed me with a 2violent curse on the day I went to Mahanaim. But when 3he came down to me at the Jordan, I swore to him by the Lord, saying, ‘I will not put you to death with the sword.’ 9Now therefore, do not let him go unpunished, 4for you are a wise man; and you will know what you ought to do to him, and you will bring his gray hair down to 5Sheol with blood.”