Exodus 7:3-6

And I will harden Pharaoh’s heart, and multiply my signs and my wonders in the land of Egypt. But 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. And the Egyptians shall know that I am Jehovah, when I stretch forth my hand upon Egypt, and bring out the children of Israel from among them. And Moses and Aaron did so; as Jehovah commanded them, so did they.