Deuteronomy 20:15
Thus shalt thou do unto all the cities which are very far off from thee, which are not of the cities of these nations. Thus shalt thou do unto all the cities which are very far off from thee, which are not of the cities of these nations.
The verse sets apart cities lying very far off as outside the group of cities belonging to the nations marked for dispossession. The course prescribed for those distant cities was to be followed toward every city of that same distant kind. Within that setting the surrounding command required the complete destruction of the Canaanites as uncircumcised enemies of God. That destruction stands as a likeness of the final destruction to come upon all the wicked who display the same spirit.