שמואל ב, פרק י׳, פסוק ט׳

Caught in a deeply complex military trap, the Israelite commander Joab faces a sudden two-front war. Surrounded by enemies, he is forced to split his troops and devise a careful strategy to survive. The looming threat is understood either as the physical battlefront itself [ביאור שטיינזלץ], or as the literal faces of the enemy warriors pressing in on the Israelite camp [מצודת דוד, רד״ק].

This double arena positions Joab between two distinct dangers. In the open field stands the Aramean army, while behind him, the Ammonites are gathered at the entrance to their city gate [אברבנאל]. Joab realizes the severe danger of his position. If he advances toward the city to attack the Ammonites, he risks being struck from behind by the Arameans, leaving his men crushed between two powerful forces. Relying on his military experience, he decides to strike the Aramean kings in the open field first [מלבי״ם].

To execute this plan, Joab selects an elite unit of Israelite warriors [ביאור שטיינזלץ]. He assigns these top soldiers to face the Arameans because their army in the field is larger, stronger, and more highly trained [אברבנאל, ביאור שטיינזלץ]. In contrast, the Ammonites draw their main strength simply from their proximity to a protected fortress.

The remainder of the Israelite army, consisting of the less experienced troops, is placed under the command of Joab's brother, Abishai, to hold the line against the Ammonites at the city gate. Joab calculates that if the Ammonites dare to leave their fortress and enter the open field, Abishai’s forces will be sufficient to defeat them. Furthermore, this secondary unit stands as a reserve guard, ready to assist in the fight against the Arameans if the situation demands it [מלבי״ם, אברבנאל].