2 Samuel 3:27

When Abner returned to Hebron, Joab took him to one side. He brought him into an inside room. Joab acted as if he wanted to speak to him in private. But he really wanted to get even with him. That’s because Abner had spilled the blood of Joab’s brother Asahel. So Joab stabbed Abner in the stomach, and he died.