Deuteronomy 13:13-16

13that some worthless and evil men have gone out from among you and have tempted the inhabitants of their city [to sin], saying, ‘Let us go and serve other gods’ (whom you have not known),

14then you shall investigate and search out [witnesses] and ask thorough questions. If it is true and the matter is established that this loathsome thing has been done among you,

15you shall most certainly strike the inhabitants of that city with the edge of the sword, utterly destroying it and all that is in it, even its livestock with the edge of the sword.

16Then you shall collect all its spoil (plunder) into the middle of its open square and burn the city and set fire to the spoil as a whole burnt offering to the Lord your God. It shall be a ruin forever. It shall not be built again.