Abishai: Pursues and Kills Abner
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2 Samuel 2:24
But Joab and Abishai pursued Abner. By sunset, they had gone as far as the hill of Ammah opposite Giah on the way to the wilderness of Gibeon.
2 Samuel 3:30
(Joab and his brother Abishai murdered Abner because he had killed their brother Asahel in the battle at Gibeon.)