Exodus 4:10-16

Then Moses said to the Lord, “Please excuse me, but I'm not someone who is good with words—not in the past, and not from the time you have been speaking with me, your servant. My speech is slow and I don't say things well.” “Who gave people mouths?” the Lord asked him. “Who makes people deaf or dumb, able to see or blind? It's I, the Lord, who does that. Now go, and I myself will be your mouth, and I will tell you what you are to say.” “Please, Lord, send someone else!” Moses responded. The Lord got angry with Moses, and told him, “There's your brother Aaron, the Levite. I know he speaks well. He's on his way to meet you, and he'll be very happy to see you. Speak to him and tell him what to say. I will be your mouth and his mouth, and I will tell you what you are to do. Aaron will speak on your behalf to the people, as if he was your mouth, and you will be in the place of God to him.