Exodus 4:10-14
4:10 Then Moses said to the Lord, “O my Lord, I am not an eloquent man, neither in the past nor since you have spoken to your servant, for I am slow of speech and slow of tongue.”
4:11 The Lord said to him, “Who gave a mouth to man, or who makes a person mute or deaf or seeing or blind? Is it not I, the Lord?
4:12 So now go, and I will be with your mouth and will teach you what you must say.”
4:13 But Moses said, “O my Lord, please send anyone else whom you wish to send!”
4:14 Then the Lord became angry with Moses, and he said, “What about your brother Aaron the Levite? I know that he can speak very well. Moreover, he is coming to meet you, and when he sees you he will be glad in his heart.