2 Samuel 2:12-13
12-13One day Abner son of Ner set out from Mahanaim with the soldiers of Ish-Bosheth son of Saul, headed for Gibeon. Joab son of Zeruiah, with David's soldiers, also set out. They met at the Pool of Gibeon, Abner's group on one side, Joab's on the other.
14Abner challenged Joab, "Put up your best fighters. Let's see them do their stuff."
Joab said, "Good! Let them go at it!"