Exodus 7:13, 16, 22

And Pharaoh’s heart was hardened, and he hearkened not unto them; as Jehovah had spoken.

And thou shalt say unto him, Jehovah, the God of the Hebrews, hath sent me unto thee, saying, Let my people go, that they may serve me in the wilderness: and, behold, hitherto thou hast not hearkened.

And the magicians of Egypt did in like manner with their enchantments: and Pharaoh’s heart was hardened, and he hearkened not unto them; as Jehovah had spoken.