Exodus 3:11

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. And the LORD said unto him, Who hath made man's mouth? or who maketh the dumb, or deaf, or the seeing, or the blind? have not I the LORD? Now therefore go, and I will be with thy mouth, and teach thee what thou shalt say. And he said, O my LORD, send, I pray thee, by the hand of him whom thou wilt send.

And Moses spake before the LORD, saying, Behold, the children of Israel have not hearkened unto me; how then shall Pharaoh hear me, who am of uncircumcised lips?

And David said unto Saul, Who am I? and what is my life, or my father's family in Israel, that I should be son in law to the king?

Then went king David in, and sat before the LORD, and he said, Who am I, O Lord GOD? and what is my house, that thou hast brought me hitherto?

And now, O LORD my God, thou hast made thy servant king instead of David my father: and I am but a little child: I know not how to go out or come in.

Then said I, Woe is me! for I am undone; because I am a man of unclean lips, and I dwell in the midst of a people of unclean lips: for mine eyes have seen the King, the LORD of hosts. Then flew one of the seraphims unto me, having a live coal in his hand, which he had taken with the tongs from off the altar: And he laid it upon my mouth, and said, Lo, this hath touched thy lips; and thine iniquity is taken away, and thy sin purged. Also I heard the voice of the Lord, saying, Whom shall I send, and who will go for us? Then said I, Here am I; send me.

Then said I, Ah, Lord GOD! behold, I cannot speak: for I am a child.