I read the op, rightly or wrongly, as a question of whether the reference of 'foreign women' was an ethnic or spiritual distinction, in light of other scripture that apparently 'overlooks' ethnic distinctions. Although I'm well away of the majority view that it is ethnic however, I have become apprehensive toward following the majority opinion, and do take the liberty graciously afforded me and conclude it (must be an spiritual issue, and thus agrees with not only the account of Ruth but also NT verse reference in the OP.