Exodus 7:13, 16, 22

Still Pharaoh’s heart was hardened, and he would not listen to them, as the LORD had said.

And you shall say to him, ‘The LORD, the God of the Hebrews, sent me to you, saying, “Let my people go, that they may serve me in the wilderness.” But so far, you have not obeyed.

But the magicians of Egypt did the same by their secret arts. So Pharaoh’s heart remained hardened, and he would not listen to them, as the LORD had said.