1 Kings 2:32-33

32And Jehovah shall requite the blood which he shed upon his own head, because he fell upon two men more righteous and better than he, and slew them with the sword, without my father David's knowledge: Abner the son of Ner, captain of the host of Israel, and Amasa the son of Jether, captain of the host of Judah.

33And their blood shall be requited upon the head of Joab, and upon the head of his seed for ever; but upon David, and upon his seed, and upon his house, and upon his throne, shall there be peace for ever from Jehovah.