2 Samuel 10:7-11

When David heard about this, he sent Joab and all the army, the warriors.

And the sons of Ammon came out and lined up for battle at the entrance of the city, while the Arameans of Zobah and of Rehob and the men of Tob and Maacah were stationed by themselves in the field.

Now when Joab saw that the battle was set against him at the front and at the rear, he selected warriors from all the choice men in Israel, and lined them up against the Arameans.

But the remainder of the people he placed under the command of his brother Abishai, and he lined them up against the sons of Ammon.

And he said, “If the Arameans are too strong for me, then you shall help me; but if the sons of Ammon are too strong for you, then I will come to help you.