Exodus 9:27

9:27 So Pharaoh sent and summoned Moses and Aaron and said to them, “I have sinned this time! The Lord is righteous, and I and my people are guilty.

Exodus 9:34-35

9:34 When Pharaoh saw that the rain and hail and thunder ceased, he sinned again: both he and his servants hardened their hearts. 9:35 So Pharaoh’s heart remained hard, and he did not release the Israelites, as the Lord had predicted through Moses.