Exodus 7:2-5

2You are to speak all that I command you, and your brother Aaron is to tell Pharaoh to let the Israelites go out of his land.

3But I will harden Pharaoh’s heart, and though I will multiply My signs and wonders in the land of Egypt, 4Pharaoh will not listen to you.

Then I will lay My hand on Egypt, and by mighty acts of judgment I will bring the divisions of My people the Israelites out of the land of Egypt. 5And the Egyptians will know that I am the LORD, when I stretch out My hand against Egypt and bring the Israelites out from among them.”