1 Then the LORD said to Moses, “See, I make you as God to Pharaoh, and your brother Aaron shall be your prophet. 2 “You shall speak all that I command you, and your brother Aaron shall speak to Pharaoh that he let the sons of Israel go out of his land. 3 “But I will harden Pharaoh’s heart that I may multiply My signs and My wonders in the land of Egypt. 4 “When Pharaoh does not listen to you, then I will lay My hand on Egypt and bring out My hosts, My people the sons of Israel, from the land of Egypt by great judgments. 5 “The Egyptians shall know that I am the LORD, when I stretch out My hand on Egypt and bring out the sons of Israel from their midst.” 6 So Moses and Aaron did it; as the LORD commanded them, thus they did. 7 Moses was eighty years old and Aaron eighty-three, when they spoke to Pharaoh.
Moses was worried about his lack of eloquence, but God was not worried about that. In verse five, he says, ‘The Egyptians shall know that I am the Lord…” God will make Himself known, even if we think we are not skilled enough to be used in that effort. God can use anyone who is willing.