Exodus 7:1-4

1And Jehovah said to Moses, See, I have made thee 1God to Pharaoh; and Aaron thy brother shall be thy prophet.

2Thou shalt speak all that I command thee; and Aaron thy brother shall speak unto Pharaoh, that he let the children of Israel go out of his land.

3And I will render Pharaoh's heart obdurate, and multiply my signs and my wonders in the land of Egypt.

4And Pharaoh will not hearken unto you; and I will lay my hand upon Egypt, and bring forth my hosts, my people, the children of Israel, out of the land of Egypt by great judgments.