Exodus 7:3-5

3But I will harden Pharaoh’s heart, and though I multiply my signs and wonders in Egypt, 4he will not listen to you. Then I will lay my hand on Egypt and with mighty acts of judgment I will bring out my divisions, my people the Israelites.

5And the Egyptians will know that I am the LORD when I stretch out my hand against Egypt and bring the Israelites out of it.”