2 Samuel 2:8-11, 12-13

In the meantime, Abner son of Ner, commander of Saul’s army, had taken Saul’s son Ish-Bosheth to Mahanaim and made him king over Gilead, over Asher, over Jezreel, over Ephraim, over Benjamin—king, as it turns out, over all Israel. Ish-Bosheth, Saul’s son, was forty years old when he was made king over Israel. He lasted only two years. But the people of Judah stuck with David. David ruled the people of Judah from Hebron for seven and a half years.

One 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.