2 Samuel 3:21

3:21 Abner said to David, “Let me leave so that I may go and gather all Israel to my lord the king so that they may make an agreement with you. Then you will rule over all that you desire.” So David sent Abner away, and he left in peace.

2 Samuel 3:27

3:27 When Abner returned to Hebron, Joab took him aside at the gate as if to speak privately with him. Joab then stabbed him in the abdomen and killed him, avenging the shed blood of his brother Asahel.