Exodus 8:15

But when Pharaoh saw that there was relief, he hardened his heart and did not listen to them, as the Lord had said.

Exodus 7:4

When Pharaoh does not listen to you, then I will lay My hand on Egypt and bring out My hosts, My people the sons of Israel, from the land of Egypt by great judgments.

Ecclesiastes 8:11

Because the sentence against an evil deed is not executed quickly, therefore the hearts of the sons of men among them are given fully to do evil.

Exodus 4:21

The Lord said to Moses, “When you go back to Egypt see that you perform before Pharaoh all the wonders which I have put in your power; but I will harden his heart so that he will not let the people go.

Exodus 7:13-14

Yet Pharaoh’s heart was hardened, and he did not listen to them, as the Lord had said.

Exodus 14:5

When the king of Egypt was told that the people had fled, Pharaoh and his servants had a change of heart toward the people, and they said, “What is this we have done, that we have let Israel go from serving us?”

Proverbs 29:1

A man who hardens his neck after much reproof
Will suddenly be broken beyond remedy.

Isaiah 26:10

Though the wicked is shown favor,
He does not learn righteousness;
He deals unjustly in the land of uprightness,
And does not perceive the majesty of the Lord.

Jeremiah 34:7-11

when the army of the king of Babylon was fighting against Jerusalem and against all the remaining cities of Judah, that is, Lachish and Azekah, for they alone remained as fortified cities among the cities of Judah.

Hosea 6:4

What shall I do with you, O Ephraim?
What shall I do with you, O Judah?
For your loyalty is like a morning cloud
And like the dew which goes away early.

Zechariah 7:11-12

But they refused to pay attention and turned a stubborn shoulder and stopped their ears from hearing.

Hebrews 3:8

Do not harden your hearts as when they provoked Me,
As in the day of trial in the wilderness,

Hebrews 3:15

while it is said,
Today if you hear His voice,
Do not harden your hearts, as when they provoked Me.”

Revelation 16:9

Men were scorched with fierce heat; and they blasphemed the name of God who has the power over these plagues, and they did not repent so as to give Him glory.

Treasury of Scripture Knowledge

Summary

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

Bible References

He hardened

Exodus 4:21
The Lord said to Moses, “When you go back to Egypt see that you perform before Pharaoh all the wonders which I have put in your power; but I will harden his heart so that he will not let the people go.
Exodus 7:4
When Pharaoh does not listen to you, then I will lay My hand on Egypt and bring out My hosts, My people the sons of Israel, from the land of Egypt by great judgments.
Proverbs 29:1
A man who hardens his neck after much reproof
Will suddenly be broken beyond remedy.
Zechariah 7:11
But they refused to pay attention and turned a stubborn shoulder and stopped their ears from hearing.
Hebrews 3:8
Do not harden your hearts as when they provoked Me,
As in the day of trial in the wilderness,
Revelation 16:9
Men were scorched with fierce heat; and they blasphemed the name of God who has the power over these plagues, and they did not repent so as to give Him glory.

General references

Exodus 7:13
Yet Pharaoh’s heart was hardened, and he did not listen to them, as the Lord had said.
Exodus 8:32
But Pharaoh hardened his heart this time also, and he did not let the people go.
Jeremiah 34:11
But afterward they turned around and took back the male servants and the female servants whom they had set free, and brought them into subjection for male servants and for female servants.