Joshua 8:10-13

Early the next morning Joshua mustered his army, and he and the leaders of Israel marched before them to Ai. The entire force that was with him marched up and approached the city and arrived in front of it. They set up camp north of Ai, with the valley between them and the city. Joshua had taken about five thousand men and set them in ambush between Bethel and Ai, to the west of the city. So 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.