2 Samuel 17:25-26

25And Absalom made Amasa captain of the army instead of Joab. This Amasa was the son of a man whose name was Jithra, an Israelite, who had gone in to Abigail the daughter of Nahash, sister of Zeruiah, Joab’s mother.

26So Israel and Absalom encamped in the land of Gilead.