Charles Ellicott 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)

See, I have made thee a god to Pharaoh ... — This is God’s answer to the objection of Moses that his lips were uncircumcised (Exodus 6:12), and probably followed it immediately. The force of it would seem to be: “You are not called on to speak, but to act. In action you will be to Pharaoh as a god—powerful, wonder-working, irresistible; it is Aaron who will have to speak to him, and he is eloquent” (Exodus 4:14).

Thy prophet. —Or spokesman— the declarer of your mind, which is the primary sense of “prophet.”