Joshua 8:13-15

13So the soldiers took up their positions—with the main camp to the north of the city and the ambush to the west of it. That night Joshua went into the valley. 14When the king of Ai saw this, he and all the men of the city hurried out early in the morning to meet Israel in battle at a certain place overlooking the Arabah. But he did not know that an ambush had been set against him behind the city. 15Joshua and all Israel let themselves be driven back before them, and they fled toward the wilderness.