Exodus 8:32

And Pharaoh hardened his heart at this time also, neither would he let the people go.

Exodus 8:15

But when Pharaoh saw that there was respit, he hardened his heart, and hearkened not to them, as the LORD had said.

Exodus 4:21

And the LORD said to Moses, When thou goest to return into Egypt, see that thou perform all those wonders before Pharaoh which I have put in thy hand: but I will harden his heart, that he shall not let the people go.

Exodus 7:13-14

And he hardened Pharaoh's heart that he hearkened not to them; as the LORD had said.

Exodus 8:8

Then Pharaoh called for Moses and Aaron, and said, Entreat the LORD that he may take away the frogs from me, and from my people: and I will let the people go, that they may do sacrifice to the LORD.

Isaiah 63:17

O LORD, why hast thou made us to err from thy ways, and hardened our heart from thy fear? Return for thy servants' sake, the tribes of thy inheritance.

Acts 28:26-27

Saying, Go to this people, and say, Hearing ye shall hear, and shall not understand; and seeing ye shall see, and not perceive.

Romans 2:5

But after thy hardness and impenitent heart, treasurest up to thyself wrath against the day of wrath, and revelation of the righteous judgment of God;

James 1:13-14

Let no man say when he is tempted, I am tempted by God: for God cannot be tempted with evil, neither tempteth he any man:

Treasury of Scripture Knowledge

Summary

And Pharaoh hardened his heart at this time also, neither would he let the people go.

Bible References

General references

Exodus 8:15
But when Pharaoh saw that there was respit, he hardened his heart, and hearkened not to them, as the LORD had said.
Exodus 4:21
And the LORD said to Moses, When thou goest to return into Egypt, see that thou perform all those wonders before Pharaoh which I have put in thy hand: but I will harden his heart, that he shall not let the people go.
Exodus 7:13
And he hardened Pharaoh's heart that he hearkened not to them; as the LORD had said.
Isaiah 63:17
O LORD, why hast thou made us to err from thy ways, and hardened our heart from thy fear? Return for thy servants' sake, the tribes of thy inheritance.
Acts 28:26
Saying, Go to this people, and say, Hearing ye shall hear, and shall not understand; and seeing ye shall see, and not perceive.
Romans 2:5
But after thy hardness and impenitent heart, treasurest up to thyself wrath against the day of wrath, and revelation of the righteous judgment of God;
James 1:13
Let no man say when he is tempted, I am tempted by God: for God cannot be tempted with evil, neither tempteth he any man: