Exodus 4:8, 9, 15, 16
Exodus 4:8 NIV
Then the LORD said, “If they do not believe you or pay attention to the first sign, they may believe the second.
Exodus 4:15 NIV
You shall speak to him and put words in his mouth; I will help both of you speak and will teach you what to do.
Exodus 4:16 NIV
He will speak to the people for you, and it will be as if he were your mouth and as if you were God to him.