Exodus 6:12
“And Moses spake before the Lord, saying, Behold, the children of Israel have not hearkened unto me; how then shall Pharaoh hear me, who am of uncircumcised lips?”
And the Lord spake unto Moses, saying,
Go in, speak unto Pharaoh king of Egypt, that he let the children of Israel go out of his land.
And Moses spake before the Lord, saying, Behold, the children of Israel have not hearkened unto me; how then shall Pharaoh hear me, who am of uncircumcised lips?
And the Lord spake unto Moses and unto Aaron, and gave them a charge unto the children of Israel, and unto Pharaoh king of Egypt, to bring the children of Israel out of the land of Egypt.
These be the heads of their fathers’ houses: The sons of Reuben the firstborn of Israel; Hanoch, and Pallu, Hezron, and Carmi: these be the families of Reuben.
Counter-Arguments
The strongest case that this verse does not belong in this theme.

Cross-References
“And Moses said unto God, Who am I, that I should go unto Pharaoh, and that I should bring forth the children of Israel out of Egypt?”
“And Moses said unto the Lord, O my Lord, I am not eloquent, neither heretofore, nor since thou hast spoken unto thy servant: but I am slow of speech, and of a slow tongue.”
“And Moses said unto the Lord, O my Lord, I am not eloquent, neither heretofore, nor since thou hast spoken unto thy servant: but I am slow of speech, and of a slow tongue.”
“To whom shall I speak, and give warning, that they may hear? behold, their ear is uncircumcised, and they cannot hearken: behold, the word of the Lord is unto them a reproach; they have no delight in it.”
“Then said I, Ah, Lord God! behold, I cannot speak: for I am a child.”