The moment God calls a commandment they are obligated to or a sin a sin it is an act of mercy on them.
In short what God commands is what God wants done, hence he commands it.
If anywhere God did not command anyone and no disobedience was involved I would whole heartedly agree with you.
God is not a fake liar commanding something which is REALLEY WANTING IT DONE and then making sure it impossible to deliver.
If he didn't want it done he would not command it so.
