Joshua 8:8

And it shall be, when ye have taken the city
Entered it and become masters of it:

[that] ye shall set the city on fire;
not the whole city, only some outlying houses of it, to make a smoke which might be seen both by Israel and the men of Ai, for different purposes; for the spoil of the city was first to be taken before it was utterly burnt with fire:

according to the commandment of the Lord shall ye do;
plunder the city, destroy the inhabitants of it, and then burn it:

see I have commanded you;
delivered the command of the Lord unto them, and therefore were left without excuse, and could not plead ignorance; besides, he was their general, and he expected his orders to be obeyed, as they ought to have been.