NOTES for Exo 4:1-31
Moses does not want to go to Egypt. He does not want to take up the work God has entrusted to him. This is understandable, and in this case hardly anyone would condemn Moses. Moses knows that he is not a prophet. When he says of himself that he is "slow of speech," Moses hardly meant some problem with speech as such. The matter was most likely something else: he did not possess the gift of prophetic speech. In those days, the path of a prophet was noticeably different from the path of an ordinary person, and the differences appeared rather early. Usually a person experienced a prophetic calling in adolescence or early youth, and after such a calling his life no longer resembled the life of an ordinary person.
The prophet would go into the wilderness, usually becoming a disciple of some other prophet, and would live with him until his death; then he himself would become a prophet and his teacher's successor. His life seemed mysterious and unusual to others: ecstasies, visions, inspired preaching, usually in poetic form, often severe, carrying warnings of coming disasters. There was nothing like this in Moses' life; he was an ordinary man. If he had come to his own people and told them that he was a prophet, they would not have believed him.
That is why God gives him the power to demonstrate certain "wonders" which, in essence, are nothing other than simple tricks with some magical element, but which were supposed to make an indelible impression on Moses' kinsmen. The matter, however, was not only in them, but also in Moses himself. He, too, is a man of his time. For him, too, prophetic ministry is associated with a definite, concrete form, outside of which he cannot imagine it. He, a prophet?
Such a thing would not fit into Moses' mind. It simply could not be. That is why Moses asks God to "find someone else." God answers His future servant that it is not the form that makes a person a prophet, but He, the God of Israel; it is He who gives a person both speech and everything else needed in order to be a prophet. Moses is still afraid all the same: habit is second nature, and it is very hard to free oneself from familiar stereotypes.
In time this will happen, but for now God calls Aaron to help Moses. Judging by the fact that Aaron had lived for a long time somewhere in the wilderness, and by the fact that he "can speak," Aaron was a "real," "proper" prophet, the kind a prophet was supposed to be according to the ideas of that time. If Moses still cannot bring himself to go alone, then so be it: he will go to carry out God's work together with his brother. The main thing is that he still goes and takes up the task entrusted to him by God.