When Abner returned to Hebron, Joab pulled him aside into the gateway, as if to speak to him privately, and there Joab stabbed him in the stomach. So Abner died on account of the blood of Joab’s brother Asahel.
Jewish Publication Society of America Version (JPS1917) - 2 Samuel 3:27 >And when Abner was returned to Hebron, Joab took him aside into the midst of the gate to speak with him quietly, and smote him there in the groin, that he died, for the blood of Asahel his brother.