1 Chronicles 19:7-9

7They hired thirty-two thousand chariots and the king of Maacah with his army, who came and camped near Medeba. The Ammonites also came together from their cities for the battle.

8David heard about this and sent Joab and all the elite troops.

9The Ammonites marched out and lined up in battle formation at the entrance of the city while the kings who had come were in the field by themselves.