NET
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.
Darby
27 And when Abner was returned to Hebron, Joab took him aside in the gate to speak with him secretly, and smote him there in the belly, that he died, for the blood of Asahel his brother.
KJV
27 And when Abner was returned to Hebron, Joab took him aside in the gate to speak with him quietly, and smote him there under the fifth [rib], that he died, for the blood of Asahel his brother.