35 So Pharaoh’s heart was hard and he would not let the Israelites go, just as the LORD had said through Moses.

Read Exodus 9:35 Using Other Translations

And the heart of Pharaoh was hardened, neither would he let the children of Israel go; as the LORD had spoken by Moses.
So the heart of Pharaoh was hardened, and he did not let the people of Israel go, just as the LORD had spoken through Moses.
Because his heart was hard, Pharaoh refused to let the people leave, just as the LORD had predicted through Moses.