1 Chronicles 19:8-13

8And David heard [of it], and he sent Joab, and all the host, the mighty men.

9And the children of Ammon came out, and put the battle in array at the entrance of the city; and the kings that had come were by themselves on the field.

10And Joab saw that the front of the battle was against him before and behind; and he chose out of all the choice men of Israel, and put them in array against the Syrians;

11and the rest of the people he gave into the hand of Abishai his brother, and they set themselves in array against the children of Ammon.

12And he said, If the Syrians be too strong for me, then thou shalt help me; and if the children of Ammon be too strong for thee, then I will help thee.

13Be strong, and let us shew ourselves valiant for our people, and for the cities of our 1God; and Jehovah will do what is good in his sight.