(Sermon starts at 31:30 in the recording).

8 Now the Lord said to Joshua: “Do not be afraid, nor be dismayed; take all the people of war with you, and arise, go up to Ai. See, I have given into your hand the king of Ai, 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 cattle you shall take as booty for yourselves. Lay an ambush for the city behind it.”

³ So Joshua arose, and all the people of war, to go up against Ai; and Joshua chose thirty thousand mighty men of valor and sent them away by night. ⁴ And he commanded them, saying: “Behold, you shall lie in ambush against the city, behind the city. Do not go very far from the city, but all of you be ready. ⁵ Then I and all the people who are with me will approach the city; and it will come about, when they come out against us as at the first, that we shall flee before them. ⁶ For they will come out after us till we have drawn them from the city, for they will say, ‘They are fleeing before us as at the first.’ Therefore we will flee before them. ⁷ Then you shall rise from the ambush and seize the city, for the Lord your God will deliver it into your hand. ⁸ And it will be, when you have taken the city, that you shall set the city on fire. According to the commandment of the Lord you shall do. See, I have commanded you.”

⁹ Joshua therefore sent them out; and they went to lie in ambush, and stayed between Bethel and Ai, on the west side of Ai; but Joshua lodged that night among the people. ¹⁰ Then Joshua rose up 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 people of war who were with him went up and drew near; and they came before the city and camped on the north side of Ai. Now a valley lay between them and Ai. ¹² So he took about five thousand men and set them in ambush between Bethel and Ai, on the west side of ^[a]the city. ¹³ And when they had set the people, all the army that was on the north of the city, and its rear guard on the west of the city, Joshua went that night into the midst of the valley.

¹⁴ Now it happened, when the king of Ai saw it, that the men of the city hurried and rose early and went out against Israel to battle, he and all his people, at an appointed place before the plain. But he did not know that there was an ambush against him behind the city. ¹⁵ And Joshua and all Israel made as if they were beaten before them, and fled by the way of the wilderness. ¹⁶ So all the people who were in Ai were called together to pursue them. And they pursued Joshua and were drawn away from the city. ¹⁷ There was not a man left in Ai or Bethel who did not go out after Israel. So they left the city open and pursued Israel.

¹⁸ Then the Lord said to Joshua, “Stretch out the spear that is in your hand toward Ai, for I will give it into your hand.” And Joshua stretched out the spear that was in his hand toward the city. ¹⁹ So those in ambush arose quickly out of their place; they ran as soon as he had stretched out his hand, and they entered the city and took it, and hurried to set the city on fire. ²⁰ And when the men of Ai looked behind them, they saw, and behold, the smoke of the city ascended to heaven. So they had no power to flee this way or that way, and the people who had fled to the wilderness turned back on the pursuers.

Joshua 8:1-20 (NKJV)