And he commanded them, saying, Behold, ye shall lie in wait against the city, even behind the city: go not very far from the city, but be ye all ready:
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.
Commenting on Joshua 8:3-22
And he commanded them, saying,.... At the time he sent them away: behold, ye shall lie in wait against the city, even behind the city; that is, on the west side of it, Jos 8:9, go not very far from the city, but be ye all ready; to enter into it, as soon as the forces are drawn out eastward to meet the army of Israel.
behind the city--is rendered (Jos 8:9), "on the west side of Ai."