Joshua 8:18 (KJV)

And all the people that were in Ai were called together to pursue after them: and they pursued after Joshua, and were drawn away from the city.

And there was not a man left in Ai or Beth–el, that went not out after Israel: and they left the city open, and pursued after Israel.

And the Lord said unto Joshua, Stretch out the spear that is in thy hand toward Ai; for I will give it into thine hand. And Joshua stretched out the spear that he had in his hand toward the city.

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

And when the men of Ai looked behind them, they saw, and, behold, the smoke of the city ascended up to heaven, and they had no power to flee this way or that way: and the people that fled to the wilderness turned back upon the pursuers.