2 Samuel 3:27 (BSB)

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.

From 2 Samuel 3. Also in the ESV.

Commentary on 2 Samuel 3:27

• Matthew Henry (Presbyterian), Matthew Henry's Complete Commentary on 2 Samuel 3:22-39: We have here an account of the murder of Abner by Joab, and David's deep resentment of it. I. Joab very insolently fell foul upon David for treating with Abner. He happened to be abroad upon service when Abner was with David, pursuing a troop, either of Philistines or of Saul's party; but, upon his return, he was informed that Abner was just gone (Sa2...
• John Gill (Reformed Baptist), Exposition of the Old and New Testaments on 2 Samuel 3:27: 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...
• Adam Clarke (Methodist), Clarke's Commentary on the Bible on 2 Samuel 3:27: And smote him there - Joab feared that, after having rendered such essential services to David, Abner would be made captain of the host: he therefore determined to prevent it by murdering the man, under pretense of avenging the death of his brother Asahel.
• Keil & Delitzsch (Lutheran), Biblical Commentary on the Old Testament on 2 Samuel 3:6-39: 2Sa 3:6-39 Decline of the House of Saul. - 2Sa 3:6-11. Abner’s quarrel with Ishbosheth. - During the war between the house of Saul and the house of David, Abner adhered firmly to the house of Saul, but he appropriated one of Saul’s concubines to himself.