1 Chronicles 19:7-9

7So they hired thirty and two thousand chariots, and the king of Maachah 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 before the gate of the city: and the kings that had come were by themselves in the field.