1 Kings 2:8-9

8“Keep an eye on Shimei son of Gera, the Benjaminite from Bahurim who is with you. He uttered malicious curses against me the day I went to Mahanaim. But he came down to meet me at the Jordan River, and I swore to him by the Lord, ‘I will never kill you with the sword.’

9So don’t let him go unpunished, for you are a wise man. You know how to deal with him to bring his gray head down to Sheol with blood.”