Exodus 3:9-12

And now, behold, the cry of the children of Israel is come unto me: moreover I have seen the oppression wherewith the Egyptians oppress them. Come now therefore, and I will send thee unto Pharaoh, that thou mayest bring forth my people the children of Israel out of Egypt. And Moses said unto God, Who am I, that I should go unto Pharaoh, and that I should bring forth the children of Israel out of Egypt? And he said, Certainly I will be with thee; and this shall be the token unto thee, that I have sent thee: when thou hast brought forth the people out of Egypt, ye shall serve God upon this mountain.