Exodus 7:2-5

2Tell your brother Aaron everything I command you, and he must tell Pharaoh to let the Israelites leave the country.

3But I will make Pharaoh stubborn. Even though I will do many miraculous signs and amazing things in Egypt,

4Pharaoh will not listen to you. Then I will use my power to punish Egypt severely, and I will bring my people, the Israelites, out of Egypt in organized family groups.

5The Egyptians will know that I am the Lord when I use my power against Egypt and bring the Israelites out of there.”