2 Samuel 2:13

2:13 Joab son of Zeruiah and the servants of David also went out and confronted them at the pool of Gibeon. One group stationed themselves on one side of the pool, and the other group on the other side of the pool.

2 Samuel 3:30

3:30 So Joab and his brother Abishai killed Abner, because he had killed their brother Asahel in Gibeon during the battle.