Exodus 4:14-16

Then the LORD’s anger burned against Moses and he said, “What about your brother, Aaron the Levite? I know he can speak well. He is already on his way to meet you, and he will be glad to see you. You shall speak to him and put words in his mouth; I will help both of you speak and will teach you what to do. He will speak to the people for you, and it will be as if he were your mouth and as if you were God to him.