1 Kings 2:32 in the King James Version
And the LORD shall return his blood upon his own head, who fell upon two men more righteous and better than he, and slew them with the sword, my father David not knowing thereof, 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.
Context
31 The king said to him, “Do as he has said, and fall on him, and bury him, that you may take away the blood, which Joab shed without cause, from me and from my father’s house.
32 The LORD will return his blood on his own head, because he fell on two men more righteous and better than he, and killed them with the sword, and my father David didn’t know it: Abner the son of Ner, captain of the army of Israel, and Amasa the son of Jether, captain of the army of Judah.
33 So their blood will return on the head of Joab and on the head of his offspring forever. But for David, for his offspring, for his house, and for his throne, there will be peace forever from the LORD.”