23 But the king of Ai they took alive, and brought him near to Joshua. 24 When Israel had finished killing all the inhabitants of Ai in the open wilderness where they pursued them, and all of them to the very last had fallen by the edge of the sword, all Israel returned to Ai and struck it down with the edge of the sword. 25 And all who fell that day, both men and women, were 12,000, all the people of Ai. 26 But Joshua did not draw back his hand with which he stretched out the javelin until he had devoted all the inhabitants of Ai to destruction.[1] 27 Only the livestock and the spoil of that city Israel took as their plunder, according to the word of the Lord that he commanded Joshua. 28 So Joshua burned Ai and made it forever a heap of ruins, as it is to this day. 29 And he hanged the king of Ai on a tree until evening. And at sunset Joshua commanded, and they took his body down from the tree and threw it at the entrance of the gate of the city and raised over it a great heap of stones, which stands there to this day.

Matthew Henry's Commentary on Joshua 8:23-29

Commentary on Joshua 8:23-29

(Read Joshua 8:23-29)

God, the righteous Judge, had sentenced the Canaanites for their wickedness; the Israelites only executed his doom. None of their conduct can be drawn into an example for others. Especial reason no doubt there was for this severity to the king of Ai; it is likely he had been notoriously wicked and vile, and a blasphemer of the God of Israel.