On hearing this, David sent Joab and the entire army of mighty men.

1 Chronicles 19:7
So they hired for themselves thirty-two thousand chariots, as well as the king of Maacah with his troops, who came and camped near Medeba while the Ammonites came from their cities and marched out for battle.

1 Chronicles 19:9
The Ammonites marched out and arrayed themselves for battle at the entrance to the city, while the kings who had come stayed by themselves in the open country.

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