Joshua 8:2

8:2 Do to Ai and its king what you did to Jericho and its king, except you may plunder its goods and cattle. Set an ambush behind the city!”

Joshua 8:29

8:29 He hung the king of Ai on a tree, leaving him exposed until evening. At sunset Joshua ordered that his corpse be taken down from the tree. They threw it down at the entrance of the city gate and erected over it a large pile of stones (it remains to this very day).