Under the cover of darkness, the Israelite army strategically positioned its forces around the city of Ai. The military deployment involved dividing the troops and preparing them for the upcoming battle, moving them deliberately close to the city walls.
A key component of this strategy was the ambush force stationed to the west of the city. Commentators note that the nature of this unit was rooted in cunning and deception [רש"י, מצודת ציון, רד"ק]. Acting as the rear guard of the camp [ביאור שטיינזלץ], this group of five thousand men was specifically tasked with flanking the enemy and launching a surprise attack [מלבי"ם].
As the forces took their positions, Joshua descended into the valley that same night. This movement is understood through several tactical, leadership, and spiritual lenses. On a practical level, moving into the valley allowed Joshua to draw nearer to the city [מצודת דוד] and closely supervise the operation [ביאור שטיינזלץ]. He patrolled among the guards to ensure they remained awake, actively preventing any chance of a surprise attack by the men of Ai while the Israelite soldiers slept [רד"ק]. Alternatively, this descent may have been an intentional display. By walking in the open valley, Joshua ensured the approaching army would be clearly visible to the enemy, serving as a calculated component of a broader military deception [מלבי"ם].
Beyond mere tactics, Joshua's presence in the valley was a profound act of leadership. The valley was the lowest and most dangerous area of the battlefield. By choosing to station himself and the elders in such a vulnerable spot, Joshua aimed to instill confidence in his warriors and strengthen their morale, actively dispelling any lingering fear from their prior defeat. Furthermore, this specific location positioned Joshua close enough to the hidden ambush force so they could clearly see him raise his spear as the signal to strike at the exact right moment [רלב"ג]. Alongside these practical explanations, a spiritual perspective suggests that Joshua's descent into the valley represents something deeper, symbolizing that he spent the night immersing himself in the profound depths of Jewish law [רש"י].