7On hearing this, David sent Joab and the entire army of mighty men.
8The Ammonites marched out and arrayed themselves for battle at the entrance of the city gate, while the Arameans of Zobah and Rehob and the men of Tob and Maacah were by themselves in the open country.
9When Joab saw the battle lines before him and behind him, he selected some of the best men of Israel and arrayed them against the Arameans.
10And he placed the rest of the forces under the command of his brother Abishai, who arrayed them against the Ammonites.
— 2 Samuel 10:7-10