3 And I [the Lord] will harden Pharaoh’s heart, and multiply My signs and My wonders in the land of Egypt. 4 But Pharaoh will not heed you, so that I may lay My hand on Egypt and bring My armies and My people, the children of Israel, out of the land of Egypt by great judgments. ... 34 And when Pharaoh saw that the rain, the hail, and the thunder had ceased, he [Pharaoh] sinned yet more; and he [Pharaoh]hardened his heart, he and his servants.(Exodus 7:3-4; 9:34)
There is no question that the Scriptures teach that there is a mysterious interplay between the elective, determinative sovereignty of God, and the uncoerced decision-making of the human will. It was God Who hardened Pharoah's heart. However, at the same time, and without frustrating the purposes of God, Pharoah made a conscious choice to close his ears to the truth, and choose a course of action which was self-destructive, and all this was so that God could bring about His ultimate purpose; that is to wipe the wicked from the face of the earth, and deliver His people in the midst of judgments.
This truth is much hated by those who have not fully embraced the God of the Scriptures as He has declared Himself to be. It is not a comfortable truth to those who still cling to a notion that man may choose for himself what is to be called good, and what is to be called evil.
On the other hand, God declares Himself to be: "I AM, THAT (WHO) I AM." We cannot add to His self revelation, nor can we take from His self-revelation. What He says of Himself, is. Our choice is to worship an idol of our own making, attempt to live against the flow of the whole universe, and ultimately die under the judgment of God; or to agree with God's self-revelation, submit to His sovereignty, and live within the boundaries of what God declares to be good, and what God declares to be evil; but even this choosing is a gift from God, so that no one can stand before Him and claim any contribution to their own salvation: "For it is by grace you have been saved, through faith, and not of yourselves, it is the gift of God."