1 Kings 2:32-34

32The Lord will now punish him because of the murders that he did. He used his sword to attack and kill two men, but he did not tell my father David about it. He murdered Ner's son Abner, the leader of Israel's army. He also murdered Jether's son Amasa, the leader of Judah's army. Both those men were better and more honest than Joab was.

33Joab and his descendants will always receive the punishment for those murders. But the Lord will cause David's descendants, his family and his kingdom to enjoy peace always.’

34So Jehoiada's son Benaiah went to the holy tent and he punished Joab with death. They buried Joab at his home in the wilderness.