II Samuel 10:6-11

When the people of Ammon saw that they had made themselves repulsive to David, the people of Ammon sent and hired the Syrians of Beth Rehob and the Syrians of Zoba, twenty thousand foot soldiers; and from the king of Maacah one thousand men, and from Ish-Tob twelve thousand men. Now when David heard of it, he sent Joab and all the army of the mighty men. Then the people of Ammon came out and put themselves in battle array at the entrance of the gate. And the Syrians of Zoba, Beth Rehob, Ish-Tob, and Maacah were by themselves in the field. When Joab saw that the battle line was against him before and behind, he chose some of Israel’s best and put them in battle array against the Syrians. And the rest of the people he put under the command of Abishai his brother, that he might set them in battle array against the people of Ammon. Then he said, “If the Syrians are too strong for me, then you shall help me; but if the people of Ammon are too strong for you, then I will come and help you.