Exodus 4:14-17 NIV

[14] 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. [15] 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. [16] 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. [17] But take this staff in your hand so you can perform the signs with it.”