1 Chronicles 19:8-12

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

And the children of Ammon came out, and put the battle in array before the gate of the city: and the kings that were come were by themselves in the field.

Now when Joab saw that the battle was set against him before and behind, he chose out of all the choice of Israel, and put them in array against the Syrians.

And the rest of the people he delivered unto the hand of Abishai his brother, and they set themselves in array against the children of Ammon.

And he said, If the Syrians be too strong for me, then thou shalt help me: but if the children of Ammon be too strong for thee, then I will help thee.