Exodus 6:30 in the King James Version
And Moses said before the LORD, Behold, I am of uncircumcised lips, and how shall Pharaoh hearken unto me?
Context
29 The LORD said to Moses, “I am the LORD. Tell Pharaoh king of Egypt all that I tell you.”
30 Moses said before the LORD, “Behold, I am of uncircumcised lips, and how shall Pharaoh listen to me?”