Exodus 8:32

And Pharaoh hardened his heart this time also, and he did not let the people go.

Exodus 8:15

But when Pharaoh saw that there was relief, he hardened his heart, and did not hearken to them, as LORD had spoken.

Exodus 4:21

And LORD said to Moses, When thou go back into Egypt, see that thou do before Pharaoh all the wonders which I have put in thy hand, but I will harden his heart and he will not let the people go.

Exodus 7:13-14

And Pharaoh's heart was hardened, and he did not hearken to them, as LORD had spoken.

Exodus 8:8

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

Isaiah 63:17

O LORD, why do thou make us to err from thy ways, and harden our heart from thy fear? Return for thy servants' sake, the tribes of thine inheritance.

Acts 28:26-27

saying, Go thou to this people, and say, Hearing ye will hear, and will, no, not understand, and seeing ye will see, and will, no, not perceive.

Romans 2:5

But according to thy hardness, and thy impenitent heart, thou store up wrath to thyself in the day of wrath, and revelation, and righteous judgment of God,

James 1:13-14

Let no man say when he is tempted, I am tempted by God, for God is without temptation of evils, and he himself tempts no 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 relief, he hardened his heart, and did not hearken to them, as LORD had spoken.
Exodus 4:21
And LORD said to Moses, When thou go back into Egypt, see that thou do before Pharaoh all the wonders which I have put in thy hand, but I will harden his heart and he will not let the people go.
Exodus 7:13
And Pharaoh's heart was hardened, and he did not hearken to them, as LORD had spoken.
Isaiah 63:17
O LORD, why do thou make us to err from thy ways, and harden our heart from thy fear? Return for thy servants' sake, the tribes of thine inheritance.
Acts 28:26
saying, Go thou to this people, and say, Hearing ye will hear, and will, no, not understand, and seeing ye will see, and will, no, not perceive.
Romans 2:5
But according to thy hardness, and thy impenitent heart, thou store up wrath to thyself in the day of wrath, and revelation, and righteous judgment of God,
James 1:13
Let no man say when he is tempted, I am tempted by God, for God is without temptation of evils, and he himself tempts no man.