Matthew Henry on Joshua 8:3-22
We have here an account of the taking of Ai by stratagem. The stratagem here used, we are sure, was lawful and good; God himself appointed it, and we have no reason to think but that the like is lawful and good in other wars. Here was no league broken, no treaty of peace, that the advantage was gained; no, these are sacred things, and not to be jested with, nor used to serve a turn; truth, when once it is plighted, becomes a debt even to the enemy. But in this stratagem here was no untruth told; nothing was concealed but their own counsels, which no enemy ever pretended a right to be entrusted with; nothing was dissembled, nothing counterfeited but a retreat, which was no natural or necessar…
Read the whole note in the consoleJamieson-Fausset-Brown on Joshua 8:9
between Beth-el and Ai--Beth-el, though lying quite near in the direction of west by north, cannot be seen from Tell-el-hajar; two rocky heights rise between both places, in the wady El-Murogede, just as the laying of an ambush to the west of Ai would require [VAN DE VELDE; ROBINSON].
Adam Clarke on Joshua 8:8
Ye shall set the city on fire - Probably this means no more than that they should kindle a fire in the city, the smoke of which should be an indication that they had taken it. For as the spoils of the city were to be divided among the people, had they at this time set fire to the city itself, all the property must have been consumed, for the five thousand men did not wait to save any thing, as they immediately issued out to attack the men of Ai in the rear.
John Gill on Joshua 8:9
Joshua therefore sent them forth,.... The thirty thousand chosen men:
and they went to lie in ambush; as they were ordered, Joshua 8:2,
and abode between Bethel and Ai, on the west side of Ai; for as Ai was on the east of Bethel, Joshua 7:2. Bethel must be on the west of Ai, as Jarchi notes:
but Joshua lodged that night among the people; the main body of the army, to direct them in the affair of war, how they should behave the next day, when they came to fight; and to inspire them with courage and confidence, that they might not be afraid, because of their having been smitten before by this people, so Ben Gersom; or rather that he and they might be ready in the morning to march towards Ai…