1 Kings 2:31-32

And the king said unto him, Do as he hath said, and fall upon him, and bury him; that thou mayest take away the blood, which Joab shed without cause, from me and from my father’s house. And Jehovah will return his blood upon his own head, because he fell upon two men more righteous and better than he, and slew them with the sword, and my father David knew it not, to wit, Abner the son of Ner, captain of the host of Israel, and Amasa the son of Jether, captain of the host of Judah.