Exodus 6:27-30

King James Version

²⁷ These are they which spake to Pharaoh king of Egypt, to bring out the children of Israel from Egypt: these are that Moses and Aaron.

²⁸ And it came to pass on the day when the Lord spake unto Moses in the land of Egypt,

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?