And the children of Ammon came out,.... Either out of Rabbah their metropolis, as Josephus u; or rather out of Medeba, as it seems from 1 Chronicles 19:7; a city that lay on the borders of their country, and was a frontier town, see Numbers 21:30;
and put the battle in array, at the entering in of the gate; of the city of Medeba; they were first within the city, but, upon the approach of Joab and his army, they came out and drew up in a line of battle at the gate of it:
and the Syrians of Zoba, and of Rehob, and Ishtob, and Maacah, [were] by themselves in the field; at some distance from the city, the Ammonites not choosing to trust: mercenaries in it; and perhaps they placed these ambush in the field, to get Joab between two fires, as we now express it.
u Antiqu. l. 7. c. 6. sect. 2.