John Calvin Commentary Exodus 7:1

"And Jehovah said unto Moses, See, I have made thee as God to Pharaoh; and Aaron thy brother shall be thy prophet." — Exodus 7:1 (ASV)

And the Lord said to Moses. Moses again repeats that consolation was given to him in his anxiety, and a remedy provided for his lack of faith, since he was both armed with divine authority and Aaron was appointed as his companion and assistant.

That he was “made a god to Pharaoh” means that he was equipped with supreme authority and power, by which he would cast down the tyrant’s pride.⁷⁷ God did not take anything away from Himself to transfer it to Moses, since He communicates what is uniquely His to His servants in such a way that He Himself remains complete. Indeed, whenever He seems to give up a part of His glory to His ministers, He only teaches that the power and efficacy of His Spirit will be joined with their labors, so that they will not be fruitless. Moses, therefore, was a god to Pharaoh because in him God exerted His power, so that he would be superior to the king's greatness.

It is a common Hebrew figure of speech to give the title of God to all things excellent, since He alone reigns over heaven and earth, and exalts or casts down angels, as well as humans, according to His will.

This consolation, as I have said, supported Moses in his weakness, so that, relying on God’s authority, he could fearlessly despise the king's fierceness. Reinforcement was also given to him in the person of his brother, so that his stammering would not be a hindrance to him.

It has already been remarked that Moses’s ingratitude led to half the honor being transferred to his brother, although God, in giving Aaron as his companion, so lessened Moses’s dignity as to place the younger before the first-born. The name “Prophet” is used here for an interpreter, because the prophetic office originates from God alone.

However, because God delivered through Moses to Aaron what He wished to be said or done, Aaron is made subject to Moses, just as if Moses were God. This is fitting, since those who represent God should be listened to without contradiction. This principle is made clearer in the second verse, where God restricts the power given to Moses and circumscribes it within its proper bounds. For when He directs him to speak whatever He commands, He establishes him as His minister and confines him under authority, without departing from His own rights.

⁷⁷ “The word Elohim, as the Hebrews remark, whether applied to God, or to men, or to angels, signifies judicial power.” —, as the Hebrews remark, whether applied to God, or to men, or to angels, signifies judicial power.” — Grotius in Pol.. Syn..