Exodus 4:10-17

10 Moses said to Yahweh, "Oh, Lord, I am not eloquent, neither before now, nor since you have spoken to your servant; for I am slow of speech, and of a slow tongue."

11 Yahweh said to him, "Who made man's mouth? Or who makes one mute, or deaf, or seeing, or blind? Isn't it I, Yahweh?  12 Now therefore go, and I will be with your mouth, and teach you what you shall speak."

13 He said, "Oh, Lord, please send someone else."

14 The anger of Yahweh was kindled against Moses, and he said, "What about Aaron, your brother, the Levite? I know that he can speak well. Also, behold, he comes forth to meet you. When he sees you, he will be glad in his heart.  15 You shall speak to him, and put the words in his mouth. I will be with your mouth, and with his mouth, and will teach you what you shall do.  16 He will be your spokesman to the people; and it will happen, that he will be to you a mouth, and you will be to him as God.  17 You shall take this rod in your hand, with which you shall do the signs."