Joshua 8:20
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. 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.
Joshua 8:20 belongs to the account of Israel's conquest of Ai, which followed their march from Gilgal. It belongs to Israel's renewed second attack on Ai after Achan's punishment had been executed and the divine wrath had been turned away from Israel. For this renewed attack Joshua was commanded to marshal all the men of war and advance against Ai again.
In this battle God's power was with Israel and the armies of heaven fought for them. With that help Israel's enemies were put to flight and the city was soon taken.