This discussion is taken from Barth’s discussion in Church Dogmatics III/4. From the premise that God gives commands, we can learn, first, that we and God are different; we are not, that is to say, part of God. This is because commands are not addressed to oneself, except in an extended sense in which one is treating oneself as another.
Second, commands are given to responders of a certain kind; those who can obey. This is explained in the four points that follow, called subsequently “the four Barthian constraints.” One, the commands are given to centers of agency, to responders whose obedience consists in acting and living in a certain way. These are individuals, though we can speak in an extended sense about the agency of collectives. This point about the nature of the responders is one Ockham relies on in his discussion of the question of whether God can command us not to love God. His view is that the command to love God, though its content is possible in itself, is pragmatically incoherent (a practical consideration) because it can’t be disobeyed; this is because to disobey it is already to love God. Recall that loving God entails obedience. See Ockham, Quodliberal Questions III.14. A content can be non-contradictory in itself, but contradictory as commanded. A content can also be non-contradictory as commanded, but contradictory as commanded by God. See Lucan Freppert’s The Basis of Morality according to William Ockham, who argues that this view is different from that of Scotus discussed in ch. 1.
Two, commands are to centers of agency whose obedience consists in changing how things are, or in resisting change. So they are in time, since, as Aristotle says, time is either change itself or the measure of change. They have to persist, in order to be obedient, through the hearing of the command to the obeying of it. Three, commands are given to free beings, in the sense of beings who are not under external causation in their obedience. Four, the responder has to be part of a language community. Commands are standardly addressed to the responder in language, and language is a communal enterprise.
So we and God are different is the first implication of our being commanded by God; the four Barthian constraints are the next four. All of those have been points about human beings. The sixth point is about God:
If God gives us commands, and the function of commanding as a speech act is to change the world through the agency of the responder to whom the command is addressed, and if the command is an expression of the desire that the world change in this way, then we can attribute something like desires (in the broad sense) to God. More usually, theologians would say God has a will. Again, that we have a God who commands is distinctive of the Abrahamic faiths, and distinguishes them from, for example, Aristotle’s religion. Since God’s creation is also a command, it’s reasonable to say that command is the characteristic fashion by which, in the Abrahamic faiths, God relates to us, either by creating or by telling us how to live inside creation. Behind this difference with Aristotle is an even more significant one. God is not, for Aristotle, in a personal relationship with us, but the Abrahamic faiths make our relation to God personal, and mediate that relation by God’s command to us.
It’s true that God’s will and God’s command can diverge, as in the famous case of Abraham and his son. When they do, are we bound (according to DCT) by God’s will or by God’s command? We should hold ourselves bound by the command, taking it as an expression of God’s will, but this assumption can, in certain cases, be overridden by another command.
Image: By Wolfgang Sauber - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=42826104