Bible Verses About Preaching: Moses, slow of speech

Moshe said to ADONAI, "Oh, Adonai, I'm a terrible speaker. I always have been, and I'm no better now, even after you've spoken to your servant! My words come slowly, my tongue moves slowly."

ADONAI answered him, "Who gives a person a mouth? Who makes a person dumb or deaf, keen-sighted or blind? Isn't it I, ADONAI?

Now, therefore, go; and I will be with your mouth and will teach you what to say."