Deuteronomy 13:15-17

you shall surely strike the inhabitants of that city with the edge of the sword, utterly destroying it, all that is in it and its livestock—with the edge of the sword. And you shall gather all its plunder into the middle of the street, and completely burn with fire the city and all its plunder, for the LORD your God. It shall be a heap forever; it shall not be built again. So none of the accursed things shall remain in your hand, that the LORD may turn from the fierceness of His anger and show you mercy, have compassion on you and multiply you, just as He swore to your fathers