Joshua 8:24

And it came to pass, when Israel had made an end of slaying all the inhabitants of Ai in the field, in the wilderness wherein they chased them, and when they were all fallen on the edge of the sword, until they were consumed, that all the Israelites returned unto Ai, and (k) smote it with the edge of the sword.

(k) For the fire, which they had before set in the city, was not to consume it, but to signify to Joshua that they had entered.