Exodus 4:10-12

10Then 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.”

11The 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?

12So now go, and I will be with your mouth and will teach you what you must say.”