Exodus 9:35 in the King James Version
And the heart of Pharaoh was hardened, neither would he let the children of Israel go; as the LORD had spoken by Moses.
Context
34 When Pharaoh saw that the rain and the hail and the thunders had ceased, he sinned yet more, and hardened his heart, he and his servants.
35 The heart of Pharaoh was hardened, and he didn’t let the children of Israel go, just as the LORD had spoken through Moses.