And when Abner was returned to Hebron
Alone, and not the twenty men with him; not to David's court, but just to the city, to the gate of it:
Joab took him aside in the gate:
where he was waiting for him, and met him; this was a public place, where people were continually passing and repassing, and where courts of judicature used to be held; wherefore Abner might think himself safe here with Joab, and have no suspicion at all of his design, and shows how fearless Joab was of God or men:
to speak with him quietly;
peaceably, in a friendly manner, as all his gestures towards him showed; so that Abner made no difficulty of turning aside with him, supposing he had something to communicate to him from the king, which he had forgot:
and smote him under the fifth [rib], that he died;
in the same place that Abner had smote his brother, of which see ( 2 Samuel 2:23 ) ; and this he did:
for the blood of Asahel his brother;
for Abner's shedding his brother's blood; but this was not the only reason, and perhaps not the chief; but, as Josephus F8 observes, because he was fearful if Abner was received into the friendship of the king, he would be preferred unto him, and take his place as general of the army, as being an older and more experienced officer; so Procopius Gazaeus, and Theodoret.
F8 Antiqu. l. 7. c. 1. sect. 5.