1 Kings 2:5-6, 31-33

“Moreover, you also know what Joab the son of Zeruiah did to me, how he dealt with the two commanders of the armies of Israel, Abner the son of Ner, and Amasa the son of Jether, whom he killed, avenging in time of peace for blood that had been shed in war, and putting the blood of war on the belt around his waist and on the sandals on his feet. Act therefore according to your wisdom, but do not let his gray head go down to Sheol in peace.

The king replied to him, “Do as he has said, strike him down and bury him, and thus take away from me and from my father’s house the guilt for the blood that Joab shed without cause. The LORD will bring back his bloody deeds on his own head, because, without the knowledge of my father David, he attacked and killed with the sword two men more righteous and better than himself, Abner the son of Ner, commander of the army of Israel, and Amasa the son of Jether, commander of the army of Judah. So shall their blood come back on the head of Joab and on the head of his descendants forever. But for David and for his descendants and for his house and for his throne there shall be peace from the LORD forevermore.”