Exodus 4:10-15

But Moses pleaded with the LORD, “O Lord, I’m not very good with words. I never have been, and I’m not now, even though you have spoken to me. I get tongue-tied, and my words get tangled.” Then the LORD asked Moses, “Who makes a person’s mouth? Who decides whether people speak or do not speak, hear or do not hear, see or do not see? Is it not I, the LORD? Now go! I will be with you as you speak, and I will instruct you in what to say.” But Moses again pleaded, “Lord, please! Send anyone else.” Then the LORD became angry with Moses. “All right,” he said. “What about your brother, Aaron the Levite? I know he speaks well. And look! He is on his way to meet you now. He will be delighted to see you. Talk to him, and put the words in his mouth. I will be with both of you as you speak, and I will instruct you both in what to do.