The three sons of Zeruiah were there – Joab, Abishai, and Asahel. (Now Asahel was as quick on his feet as one of the gazelles in the field.)

So Joab and his brother Abishai killed Abner, because he had killed their brother Asahel in Gibeon during the battle.

So Joab and Abishai chased Abner. At sunset they came to the hill of Ammah near Giah on the way to the wilderness of Gibeon.

Amasa did not protect himself from the knife in Joab’s other hand, and Joab stabbed him in the abdomen, causing Amasa’s intestines to spill out on the ground. There was no need to stab him again; the first blow was fatal. Then Joab and his brother Abishai pursued Sheba son of Bicri.

Abishai son of Zeruiah, the brother of Joab, was head of the three. He killed three hundred men with his spear and gained fame among the three.