23 Except for the king of Ai; they took him alive and brought him to Joshua. 24 When it was all over, Israel had killed everyone in Ai, whether in the fields or in the wilderness where they had chased them. When the killing was complete, the Israelites returned to Ai and completed the devastation. 25 The death toll that day came to 12,000 men and women - everyone in Ai. 26 Joshua didn't lower his outstretched javelin until the sacred destruction of Ai and all its people was completed. 27 Israel did get to take the livestock and loot left in the city; God's instructions to Joshua allowed for that. 28 Joshua burned Ai to the ground. A "heap" of nothing forever, a "no-place" - go see for yourself. 29 He hanged the king of Ai from a tree. At evening, with the sun going down, Joshua ordered the corpse cut down. They dumped it at the entrance to the city and piled it high with stones - you can go see that also.
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.