Deuteronomy 13:15-16

15Thou shalt surely smite the inhabitants of that city with the edge of the sword, destroying it utterly, and all that is therein, and the cattle thereof, with the edge of the sword.

16And thou shalt gather all the spoil of it into the midst of the street thereof, and shalt burn with fire the city, and all the spoil thereof every whit, for Yhwh thy God: and it shall be an heap for ever; it shall not be built again.