Contradiction with Exodus 4:10
Moses initially expresses doubt in his speaking abilities, similar to his hesitance in Exodus 6:30, but later scriptures show he effectively leads and communicates with the Israelites and Pharaoh.
Exodus 4:10: 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. [eloquent: Heb. a man of words] [heretofore: Heb. since yesterday, nor since the third day]
Contradiction with Acts 7:22
This verse states that Moses was learned in all the wisdom of the Egyptians and was mighty in words and deeds, contradicting his claim of being "of uncircumcised lips" in Exodus 6:30.
Acts 7:22: And Moses was learned in all the wisdom of the Egyptians, and was mighty in words and in deeds.