1 Chronicles 19:8

6When the children of Ammon saw that they had made themselves odious to David, Hanun and the children of Ammon sent one thousand talents of silver to hire chariots and horsemen out of Mesopotamia, out of Aram-maacah, and out of Zobah.

7So they hired for themselves thirty-two thousand chariots, and the king of Maacah with his people, who came and encamped near Medeba. The children of Ammon gathered themselves together from their cities, and came to battle.

8When David heard of it, he sent Joab with all the army of the mighty men.

9The children of Ammon came out, and put the battle in array at the gate of the city; and the kings who had come were by themselves in the field.

10Now when Joab saw that the battle was set against him before and behind, he chose some of all the choice men of Israel, and put them in array against the Syrians.