Joshua 8:9-13

So Joshua sent them away, and they went to the place of ambush and remained between Bethel and Ai, on the west side of Ai; but Joshua spent that night among the people.

Now Joshua got up early in the morning and mustered the people, and he went up with the elders of Israel before the people to Ai.

Then all the people of war who were with him went up and approached, and arrived in front of the city; and they camped on the north side of Ai. And there was a valley between him and Ai.

Then he took about five thousand men and set them in ambush between Bethel and Ai, on the west side of the city.

So they stationed the people, all the army that was on the north side of the city, and its rear guard on the west side of the city, and Joshua spent that night in the midst of the valley.