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. The great fear of Moses now made him protest his oratorical inability. which made it impossible for him to do justice to the message of the Lord and therefore threatened failure to the whole plan. He lacked both the natural gift of facile speech and the practice before an audience, and this ability had not been imparted to him in the course of this conversation.