29 That the LORD spake unto Moses, saying, I am the LORD: speak thou unto Pharaoh king of Egypt all that I say unto thee.
30 And Moses said before the LORD, Behold, I am of uncircumcised lips, and how shall Pharaoh hearken unto me?
Exodus 7
1 And the LORD said unto Moses, See, I have made thee a god to Pharaoh: and Aaron thy brother shall be thy prophet.
2 Thou shalt speak all that I command thee: and Aaron thy brother shall speak unto Pharaoh, that he send the children of Israel out of his land.
3 And I will harden Pharaoh's heart, and multiply my signs and my wonders in the land of Egypt.
4 But Pharaoh shall not hearken unto you, that I may lay my hand upon Egypt, and bring forth mine armies, and my people the children of Israel, out of the land of Egypt by great judgments.
5 And the Egyptians shall know that I am the LORD, when I stretch forth mine hand upon Egypt, and bring out the children of Israel from among them.
6 And Moses and Aaron did as the LORD commanded them, so did they.
7 And Moses was fourscore years old, and Aaron fourscore and three years old, when they spake unto Pharaoh.
8 And the LORD spake unto Moses and unto Aaron, saying,
9 When Pharaoh shall speak unto you, saying, Shew a miracle for you: then thou shalt say unto Aaron, Take thy rod, and cast it before Pharaoh, and it shall become a serpent.