Exodus 8:15, 19, 32

But when Pharaoh saw that there was relief, he hardened his heart and did not listen to them, as the LORD had said.

Then the magicians said to Pharaoh, “This is the finger of God.” But Pharaoh’s heart was hardened, and he did not listen to them, as the LORD had said.

But Pharaoh hardened his heart this time also, and he did not let the people go.