I Chronicles 19:6-15

When the people of Ammon saw that they had made themselves repulsive to David, Hanun and the people of Ammon sent a thousand talents of silver to hire for themselves chariots and horsemen from Mesopotamia, from Syrian Maacah, and from Zobah. So they hired for themselves thirty-two thousand chariots, with the king of Maacah and his people, who came and encamped before Medeba. Also the people of Ammon gathered together from their cities, and came to battle. 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 before the gate of the city, and the kings who had come 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, and they set themselves 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 help you. Be of good courage, and let us be strong for our people and for the cities of our God. And may the LORD do what is good in His sight.” So Joab and the people who were with him drew near for the battle against the Syrians, and they fled before him. When the people of Ammon saw that the Syrians were fleeing, they also fled before Abishai his brother, and entered the city. So Joab went to Jerusalem.