In Joshua 8:2, God commands Joshua to destroy Ai by ambush; this verse records the fulfillment — burning the city to a permanent ruin.

In Joshua 8:8, the ambush plan includes setting the city on fire; this verse shows that command carried out.

Joshua 6:24 describes Jericho's burning — a parallel act of destruction in the conquest, though Jericho was later rebuilt and not a permanent heap.

In Deuteronomy 13:16, the law commands making an apostate city a 'heap forever' — Joshua applies that exact judgment to Ai.