Joshua 8:10-15

10Joshua arose early in the morning and mustered the people and went up, he and the elders of Israel, before the people to Ai. 11And aall the fighting men who were with him went up and drew near before the city and encamped on the north side of Ai, with a ravine between them and Ai. 12He took about 5,000 men and set them in ambush between Bethel and Ai, to the west of the city. 13So they stationed the forces, the main encampment that was north of the city and its rear guard west of the city. But Joshua spent that night in the valley. 14And as soon as the king of Ai saw this, he and all his people, the men of the city, hurried and went out early to the appointed place
Hebrew  appointed time
toward cthe Arabah to meet Israel in battle. dBut he did not know that there was an ambush against him behind the city.
15And Joshua and all Israel epretended to be beaten before them and fled in the direction of the wilderness.
Copyright information for ESV