Matthew Poole and continuators on Joshua 8:19

19 And the ambush arose quickly out of their place, and they ran assoon as he had stretched out his hand: and they entred into the city, and took it, and hasted, and set the city on fire.

i. e. Not all of it, as appears both from v. 28. and because then they had lost that Prey which God had allowed them; but some part of it, enough to raise a smoke, and give notice to their Brethren of their success.