1 Chronicles 19:7-9

7So they hired them thirty and two thousand chariots, and the king of Maacah and his people, who came and encamped before Medeba. And the children of Ammon gathered themselves together from their cities, and came to battle. 8And when David heard of it, he sent Joab, and all the host of the mighty men. 9And the children of Ammon came out, and put the battle in array at the gate of the city: and the kings that were come were by themselves in the field.