King James Version
So Joab and Abishai his brother slew Abner, because he had slain their brother Asahel at Gibeon in the battle.New International Version
(Joab and his brother Abishai murdered Abner because he had killed their brother Asahel in the battle at Gibeon.)Catholic Public Domain Version
And so, Joab and his brother Abishai killed Abner, because he had killed their brother Asahel at Gibeon, during the battle