1 Kings 2:8-9

And there is also with you Shimei the son of Gera, the Benjaminite from Bahurim, who cursed me with a grievous curse on the day when I went to Mahanaim. But when he came down to meet me at the Jordan, I swore to him by the LORD, saying, ‘I will not put you to death with the sword.’ Now therefore do not hold him guiltless, for you are a wise man. You will know what you ought to do to him, and you shall bring his gray head down with blood to Sheol.”