2 Samuel 3:26 MSG

[26] Joab left David and went into action. He sent messengers after Abner; they caught up with him at the well at Sirah and brought him back. David knew nothing of all this. When Abner got back to Hebron, Joab steered him aside at the gate for a personal word with him. There he stabbed him in the belly, killed him in cold blood for the murder of his brother Asahel.