2 Samuel 17:24-26

Then David came to Mahanaim. And Absalom crossed the Jordan with all the men of Israel. Now Absalom had set Amasa over the army instead of Joab. Amasa was the son of a man named Ithra the Ishmaelite, who had married Abigal the daughter of Nahash, sister of Zeruiah, Joab’s mother. And Israel and Absalom encamped in the land of Gilead.