Beginning of the End - Ellen G. White

But in his distress and fear the servant of God now pleaded as
an excuse a lack of speaking ability: "O my Lord, I am not eloquent.
... I am slow of speech and slow of tongue." He had been away from
the Egyptians so long that he could not speak their language as
easily as when he was among them.
Moses asked that a more competent person be chosen, but after
the Lord had promised to remove all difficulties and give him final
success, any further complaining about his unfitness showed distrust
of God. It implied a fear that God was unable to qualify him or that
He had made a mistake in His choice of the man.
Aaron, his older brother, and been speaking the language of the
Egyptians every day, and he was able to speak it perfectly. God told
Moses that Aaron was coming to meet him, and the next words from
the Lord were an unqualified command.
"You shall speak to him and put the words in his mouth. ... So
he shall be your spokesman to the people. And he himself shall be as
a mouth for you, and you shall be to him as God. And you shall take
this rod in your hand, with which you shall do the signs." Moses
could no longer resist, for all ground for excuse was removed.
Having once accepted the work, Moses entered into it with his
whole heart, putting all his trust in the Lord. God blessed his prompt
obedience, and he became eloquent, hopeful, confident, and well
prepared for the greatest work ever given to a human being.
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