2 Samuel 3:26-30 - Joab Murders Abner
26 And Joab left David and sent messengers after Abner, who brought him again from the well of Sirah. But David did not know. 27 And Abner returned to Hebron. And Joab took him aside in the gate to speak with him privately. And he struck him there in the belly, and he died, for the blood of Asahel his brother.
28 And afterward David heard, and said, My kingdom and I are guiltless before Jehovah forever from the blood of Abner the son of Ner. 29 Let it whirl about the head of Joab, and on all his father's house. And let there not fail from the house of Joab one who has an issue, or who is a leper, or who leans on a staff, or who falls on the sword, or who lacks bread. 30 And Joab and Abishai his brother killed Abner, because he had slain their brother Asahel at Gibeon in the battle.