Exodus 4:10-17

But Moses said to the LORD, “O my Lord, I have never been eloquent, neither in the past nor even now that you have spoken to your servant; but I am slow of speech and slow of tongue.” Then the LORD said to him, “Who gives speech to mortals? Who makes them mute or deaf, seeing or blind? Is it not I, the LORD? Now go, and I will be with your mouth and teach you what you are to speak.” But he said, “O my Lord, please send someone else.” Then the anger of the LORD was kindled against Moses and he said, “What of your brother Aaron, the Levite? I know that he can speak fluently; even now he is coming out to meet you, and when he sees you his heart will be glad. You shall speak to him and put the words in his mouth; and I will be with your mouth and with his mouth, and will teach you what you shall do. He indeed shall speak for you to the people; he shall serve as a mouth for you, and you shall serve as God for him. Take in your hand this staff, with which you shall perform the signs.”