Because they were accursed, as I warned and threatened them, Joshua 6:18, they have put themselves out of my protection and blessing, and therefore are liable to the same destruction which belongs to this accursed people.
Related Commentaries of Joshua 7:12
Joshua 7:12
12 Therefore the children of Israel could not stand before their enemies, but turned their backs before their enemies, because they were accursed: neither will I be with you any more, except ye destroy the accursed from among you.