Unless you think god has established morality which it is
now bound by which means it exists outside of god.
It's my understanding--I'm hoping one of our Jewish posters can correct me if I'm mistaken about this--that in certain currents of Jewish thought this is the position of the Torah, a covenant binding on God as well as on humanity; the moral logic underlying the mitzvot isn't conditional on God's continuing to uphold it, it just
is, the way laws of physics just
are (or, for that matter, the way God Himself just
is). I was saying to Antonio privately the other day that I think this is at least as strong an a priori definition of what morality is as divine command; he observed that the problem with it is that it still doesn't provide any non-revealed grounds for getting at the content of moral facts.