1 Samuel 6:6

And I, behold, I will harden the hearts of the Egyptians, and they shall follow them: and I will get me honour upon Pharaoh, and upon all his host, upon his chariots, and upon his horsemen.

And he hardened Pharaoh’s heart, that he hearkened not unto them; as the Lord had said.

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

And when Pharaoh saw that the rain and the hail and the thunders were ceased, he sinned yet more, and hardened his heart, he and his servants.

And Moses and Aaron came in unto Pharaoh, and said unto him, Thus saith the Lord God of the Hebrews, How long wilt thou refuse to humble thyself before me? let my people go, that they may serve me.

And he called for Moses and Aaron by night, and said, Rise up, and get you forth from among my people, both ye and the children of Israel; and go, serve the Lord, as ye have said. Also take your flocks and your herds, as ye have said, and be gone; and bless me also. And the Egyptians were urgent upon the people, that they might send them out of the land in haste; for they said, We be all dead men.

And the Egyptians pursued, and went in after them to the midst of the sea, even all Pharaoh’s horses, his chariots, and his horsemen.

The people shall hear, and be afraid: sorrow shall take hold on the inhabitants of Palestina. Then the dukes of Edom shall be amazed; the mighty men of Moab, trembling shall take hold upon them; all the inhabitants of Canaan shall melt away. Fear and dread shall fall upon them; by the greatness of thine arm they shall be as still as a stone; till thy people pass over, O Lord, till the people pass over, which thou hast purchased.

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

And in very deed for this cause have I raised thee up, for to shew in thee my power; and that my name may be declared throughout all the earth.

But exhort one another daily, while it is called To day; lest any of you be hardened through the deceitfulness of sin.

He is wise in heart, and mighty in strength: who hath hardened himself against him, and hath prospered?

Harden not your heart, as in the provocation, and as in the day of temptation in the wilderness:

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