It can be read & observed that God does not abide by moral commands, nor does He fulfill obligations or virtues by coming under the authority of His commands (as in such the way that humans may). For God, He does as by whatever He sets to do. To say that He cannot violate His nature would also be unhelpful, as nothing can move or act beyond the scope of its genuine nature.
Divine command theory is one popular approach in Christian circles to argue for an objective basis for morality. Even if this theory were true, it could not account for why God would be moral. It would also not demonstrate a firm basis for an action being moral or immoral -- other than God just stating it as being so.
Divine command theory does comport well with
The Bible does record & announce that God is good, praiseworthy, loving, etc. Yet, it would be by presumption to regard His as a moral goodness. The Bible often uses various figures of speech and metaphor to talk about God. In fact the Bible more often than not uses physical terms to describe God. However, orthodox Christians do not regard the Father [God] to be physical, even though there are probably more descriptions of God that seem to indicate him having a material body than being merely Spirit.
God is not constrained or bound by human morality. If there were a standard that was not part of Him, its authority or strength would be insufficient to direct Him. For Him to be His own standard borders on incoherence, as by this it wouldn't matter what He did, in it He would be completely "in the right" by His doing. God is not human. We have a frightful habit as humans, of making God like us rather than holding that He is not like us: Being all-wise, all powerful, just, beyond the finite. We are finite beings that He has given a particular nature that allows us to change for better or worse, to the outflow of our actions. It should also be noted that a cooperative ethic may (over time) assemble, inspire or re-interpret moral norms or codes uniquely understood by one people group or another.
"The notion of God as subject to duties or obligations (and as acting in accordance with them) would, I think, have been thought of by [Aquinas] as an unfortunate lapse into anthropomorphism, as reducing God to the level of
God is good, metaphysically good and perfect/mature/complete. He is perfect in the sense that He is complete being and lacks nothing. Further, all other perfections that are found in creatures as effects pre-exist in such a way with him as the cause. This even includes goodness, but without making him moral. Matter pre-exists in God as its cause without God being material. But there is a sense in which that God can be said to have virtues, but in a very analogous kind of way.