Joshua 8:29

And the king of Ai he hanged on a tree until eventide: and as soon as the sun was down, Joshua commanded that they should take his carcase down from the tree, and cast it at the entering of the gate of the city, and raise thereon a great heap of stones, that remaineth unto this day.

The king of Ai he hanged on a tree - i:e., gibbetted. In ancient, and particularly Oriental wars, the chiefs, when taken prisoners, were usually executed-first slain by the sword, and then exposed on a gibbet for a time. The Israelites were obliged by the divine law (Deuteronomy 21:22, etc.) to put them to death. The execution of the king of Ai would tend to facilitate the conquest of the land, by striking terror into the other chiefs, and making it appear a judicial process, in which they were inflicting the vengeance of God upon his enemies.

Take his carcass down ... and raise thereon a great heap of stones, х gal (H1530), a cairn]. It was taken down at sunset, according to the divine command (Deuteronomy 21:23), and cast into a pit dug "at the entering of the gate," because that was the most public place. An immense cairn was raised over his grave-an ancient usage still existing in the East, whereby is marked the sepulchre of persons whose memory is infamous (see the note at Joshua 7:26).