2 Samuel 3:27

In the gate; in the entrance into the city before he came to the king; and in the place where conferences used to be. Quietly; with appearance of great civility and kindness. Or, secretly, as having some matter of great importance to utter, which none but himself must hear. Smote him there under the fifth rib; as he did Asahel, 2 Samuel 2:23. For the blood of Asahel his brother; to revenge the death of Asahel; and withal (though that be not here mentioned) to secure his own standing, and rid his hands of so great and powerful a competitor. And thus was Joab's design; but God had other designs in it, both to punish Abner's manifest wickedness, and particularly his rebellion against David, and against God and his own conscience therein; and that David might not owe his kingdom to Abner, and to his revenge and treachery, but wholly to God's wise and powerful providence.