Deuteronomy 13:15-19

you shall most certainly strike the inhabitants of that city with the edge of the sword. Utterly destroy it and all who are in it and its cattle, with the edge of the sword.

Then you shall gather all its plunder into the middle of its public square, and burn the city and all its plunder with fire as a whole burnt offering to the Lord your God; and it shall be a ruin forever. It shall never be rebuilt.

Nothing at all from what is designated for destruction is to cling to your hand, in order that the Lord may turn from His burning anger and show mercy to you, and have compassion on you and make you increase, just as He has sworn to your fathers,

if you will listen to the voice of the Lord your God, keeping all His commandments which I am commanding you today, and doing what is right in the sight of the Lord your God.