But the LORD hardened the heart of Pharaoh; and he did not heed them, just as the LORD had spoken to Moses.
Exodus 9:12
Surrounding context
9:11 And the magicians could not stand before Moses because of the boils, for the boils were on the magicians and on all the Egyptians.
9:12 But the LORD hardened the heart of Pharaoh; and he did not heed them, just as the LORD had spoken to Moses.
9:13 Then the LORD said to Moses, "Rise early in the morning and stand before Pharaoh, and say to him, "Thus says the LORD God of the Hebrews: "Let My people go, that they may serve Me,