Exodus 6:28-30
Exodus 6:28-30 AMP
Now it happened on the day when the LORD spoke to Moses in the land of Egypt, that He said, “I am the LORD; tell Pharaoh king of Egypt everything that I say to you.” But Moses said before the LORD, “Look, I am unskilled and inept in speech; how then will Pharaoh listen to me and pay attention to what I say?”