8:1 And the Lord said to Joshua, “Do not fear and do not be dismayed. Take all the fighting men with you, and arise, go up to Ai. See, I have given into your hand the king of Ai, and his people, his city, and his land. 2 And you shall do to Ai and its king as you did to Jericho and its king. Only its spoil and its livestock you shall take as plunder for yourselves. Lay an ambush against the city, behind it.”
3 So Joshua and all the fighting men arose to go up to Ai. And Joshua chose 30,000 mighty men of valor and sent them out by night. 4 And he commanded them, “Behold, you shall lie in ambush against the city, behind it. Do not go very far from the city, but all of you remain ready. 5 And I and all the people who are with me will approach the city. And when they come out against us just as before, we shall flee before them. 6 And they will come out after us, until we have drawn them away from the city. For they will say, ‘They are fleeing from us, just as before.’ So we will flee before them. 7 Then you shall rise up from the ambush and seize the city, for the Lord your God will give it into your hand. 8 And as soon as you have taken the city, you shall set the city on fire. You shall do according to the word of the Lord. See, I have commanded you.” 9 So Joshua sent them out. And they went to the place of ambush and lay between Bethel and Ai, to the west of Ai, but Joshua spent that night among the people.
10 Joshua arose early in the morning and mustered the people and went up, he and the elders of Israel, before the people to Ai. 11 And all 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. 12 He took about 5,000 men and set them in ambush between Bethel and Ai, to the west of the city. 13 So 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. 14 And 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  toward the Arabah to meet Israel in battle. But he did not know that there was an ambush against him behind the city. 15 And Joshua and all Israel pretended to be beaten before them and fled in the direction of the wilderness. 16 So all the people who were in the city were called together to pursue them, and as they pursued Joshua they were drawn away from the city. 17 Not a man was left in Ai or Bethel who did not go out after Israel. They left the city open and pursued Israel. (ESV)
 8:14 Hebrew appointed time