2 Samuel 17:24-26

David soon arrived at Mahanaim. By now, Absalom had mobilized the entire army of Israel and was leading his troops across the Jordan River. Absalom had appointed Amasa as commander of his army, replacing Joab, who had been commander under David. (Amasa was Joab’s cousin. His father was Jether, an Ishmaelite. His mother, Abigail daughter of Nahash, was the sister of Joab’s mother, Zeruiah.) Absalom and the Israelite army set up camp in the land of Gilead.