Exodus 7:14

And the LORD said unto Moses, Pharaoh’s heart is hardened, he refuseth to let the people go.
— Exodus 7:14, King James Version

In other translations

World English Bible (WEB)

Yahweh said to Moses, "Pharaoh's heart is stubborn. He refuses to let the people go.

American Standard Version (ASV)

And Jehovah said unto Moses, Pharaoh’s heart is stubborn, he refuseth to let the people go.

Young's Literal Translation (YLT)

And Jehovah saith unto Moses, 'The heart of Pharaoh hath been hard, he hath refused to send the people away;