They hired thirty-two thousand chariots and charioteers, as well as the king of Maacah with his troops, who came and camped near Medeba,1 while the Ammonites were mustered from their towns and moved out for battle.
References for 1 Chronicles 19:7
On hearing this, David sent Joab out with the entire army of fighting men.
The Ammonites came out and drew up in battle formation at the entrance to their city, while the kings who had come were by themselves in the open country.
Joab saw that there were battle lines in front of him and behind him; so he selected some of the best troops in Israel and deployed them against the Arameans.
He put the rest of the men under the command of Abishai2 his brother, and they were deployed against the Ammonites.
References for 1 Chronicles 19:11
Joab said, "If the Arameans are too strong for me, then you are to rescue me; but if the Ammonites are too strong for you, then I will rescue you.
Be strong and let us fight bravely for our people and the cities of our God. The LORD will do what is good in his sight."
Then Joab and the troops with him advanced to fight the Arameans, and they fled before him.
When the Ammonites saw that the Arameans were fleeing, they too fled before his brother Abishai and went inside the city. So Joab went back to Jerusalem.