Exodus 4:10-15

10Moses said to the LORD, “Pardon your servant, Lord. I have never been eloquent, neither in the past nor since you have spoken to your servant. I am slow of speech and tongue.” 11The LORD said to him, “Who gave human beings their mouths? Who makes them deaf or mute? Who gives them sight or makes them blind? Is it not I, the LORD ?

12Now go; I will help you speak and will teach you what to say.”

13But Moses said, “Pardon your servant, Lord. Please send someone else.” 14Then the LORD ’s anger burned against Moses and he said, “What about your brother, Aaron the Levite? I know he can speak well. He is already on his way to meet you, and he will be glad to see you. 15You shall speak to him and put words in his mouth; I will help both of you speak and will teach you what to do.