Exodus 9:35 KJV
And the heart of Pharaoh was hardened, neither would he let the children of Israel go; as the Lord had spoken by Moses.
Exodus 9:35, King James Version
In context
34 And when Pharaoh saw that the rain and the hail and the thunders were ceased, he sinned yet more, and hardened his heart, he and his servants.
35 And the heart of Pharaoh was hardened, neither would he let the children of Israel go; as the Lord had spoken by Moses.