1 Kings 2:8-9

And, behold, there is with thee Shimei the son of Gera, the Benjamite, of Bahurim, who cursed me with a grievous curse in the day when I went to Mahanaim; but he came down to meet me at the Jordan, and I sware to him by Jehovah, saying, I will not put thee to death with the sword. Now therefore hold him not guiltless, for thou art a wise man; and thou wilt know what thou oughtest to do unto him, and thou shalt bring his hoar head down to Sheol with blood.