Exodus 4:1; Exodus 4:10

1 Then Moses said, "What if they will not believe me or listen to what I say? For they may say, 'The LORD has not appeared to you.' "

10 Then Moses said to the LORD , "Please, Lord , I have never been eloquent , neither recently nor in time past, nor since You have spoken to Your servant; for I am slow of speech and slow of tongue."