1 Chronicles 19:7-9

7And they hired thirty-two thousand chariots, and the king of Maacah and his people; and they came and encamped before Medeba. And the children of Ammon gathered together from their cities, and came to battle.

8And David heard [of it], and he sent Joab, and all the host, the mighty men.

9And the children of Ammon came out, and put the battle in array at the entrance of the city; and the kings that had come were by themselves on the field.