The Scripture teaches positively that the hardening and "darkening of their foolish heart" is a divine, intentional act.
This is plainly evident from God's charge to Moses concerning the king of Egypt: "Thou shalt speak all that I command thee; and I will harden Pharaoh's heart, and multiply My signs and wonders in the land of Egypt. But Pharaoh shall not harken unto you, and I will lay My hand upon Egypt, and the Egyptians shall know that I am the Lord" (Exod. vii.3-5). Before this the Lord had said to Moses: "When thou goest to return unto Egypt, see that thou do all those wonders before Pharaoh, which I have put in thine hand; but I will make his heart stubborn, that he shall not let the people go" (Exod. iv.21).
The principal person in the Scripture in whom this awful truth obtains its clearest revelation is Pharaoh. Why in him we can not tell. And, instead of looking down on him from the heights of our own imagined piety, we should rather remember the word of the apostle: "And whom He will He hardens."
However, the subject of this terrible judgment of hardening is not the individual Pharaoh in his private life, but the king, the mighty prince and sovereign, the ruler and despot, who in the majesty of his crown and scepter represented the supremacy of the first great world-empire over the nations of the earth.
In those days Egypt occupied the position subsequently attained by Nineveh, Babylon, Macedonia, and Rome; it was the embodiment of all the luster and glory which the natural, sinful, and God-rejecting world could create. In the cities of Upper and Lower Egypt men reveled in the refined pleasures of life. From all the surrounding countries gold came pouring into Egypt. The rulers built themselves great cities and strong fortresses, sphinxes and mountain-like pyramids. Cities of the dead were hewn out of the rocks. Magnificent sarcophagi were chiseled out of exquisitely beautiful marble. In a word, the world's proud and majestic creations of those days were found on the shores of the Nile. The Pharaoh of Egypt was the mightiest man of the earth.
And as such he is the subject of the hardening. That St. Paul views the conflict between Jehovah and Pharaoh in this light is evident from his quotation of Exod. ix.16, where it is expressed in strongest and plainest language: "For I will at this time send all My plagues upon thine heart, and upon thy servants, and upon thy people; that thou mayest know that there is none like Me in all the earth. And in very deed for this cause have I raised thee up, for to show in thee My power; and that My name may be declared throughout all the earth" (Rom. ix.11).
These words are meaningless if they are made to refer to the private life of the individual Pharaoh. No private individual ever possessed such power. But if they are understood as referring to Pharaoh the great world-ruler, they assume an entirely different aspect. For he was not the creator of that power, neither was that power the creation of a day, but the result of a gradual development under God's own direction. Four centuries before Moses, God had already spoken to Abraham of this mighty Egypt and predicted the conflict which His power would bring upon it. Many dynasties of absolute monarchs had succeeded one another. And when Pharaoh's dynasty ascended the throne, the centralized government of the empire was thoroughly vested in his person.
In His unfathomable counsel the Lord had evidently led the godless world of that day to concentrate all its wisdom, power, intellect, and refinement in Egypt's limited territory. Himself had raised up Egypt, Himself had raised up its great dynasties, and lastly raised up Pharaoh, who, wholly absorbed into Egypt's luxury, power, and world-majesty, was the embodiment of what the world could oppose in one man, and he therefore a man of sin, against the majesty of God.
And this haughty monarch enclosed Israel in the bonds of death, and with them the Hope of the fathers, the preparation of Messiah after the flesh, and the Church of God in its patriarchal state. He should have honored and blessed this people, but he treated it cruelly. The sciences of those days flourished in Egypt. Historical events were chiseled in hieroglyphs upon stone, and published upon obelisks and sarcophagi for the information of the public. Hence Egypt could not plead ignorance as an excuse; at the royal court Joseph was still remembered as the benefactor of Egypt, who saved it from famine; and the Egyptians could not have forgotten their solemn promises to the Hebrews. And yet Pharaoh tyrannized over the people, and even sought to prevent their increase by ordering the destruction of all male infants.
Hence Pharaoh, enslaving Israel, represents the evil world-power which kept the Christ in bondage. Wherefore God said: "I have called My Son out of Egypt." With Israel He called the Messiah out of Egypt. The fearful conflict was for Messiah against Pharaoh.
This sheds some light upon the puzzling words: "For this cause have I raised thee up." Having lost its prop by its departure from God, the world could not manifest its sinful power but in a world-empire, and in individual monarchs. And such manifestation was not fortuitous, but a logical necessity, divinely intended, that the divine power might triumph over it. For this reason it is repeatedly stated: "But the Lord hardened Pharaoh's heart" (Exod. x.20); "And I will harden Pharaoh's heart, that he shall follow after them, and I will be honored upon Pharaoh and upon his host, that the Egyptians may know that I am the Lord" (Exod. xiv.4); "And the Lord hardened the heart of Pharaoh, and he pursued after the children of Israel" (Exod. xiv.8). Later on the hardening came upon all Egypt: "And I, behold, I will make stubborn the hearts of the Egyptians, and I will get Me honor upon pharaoh and upon all his host" (Exod. xiv.17).
Throughout this whole terrible history the prospective hardening is first announced, then carried into effect, and finally, recorded as accomplished in Pharaoh. For -- and this deserves special notice -- every announcement of the divine hardening is followed by the announcement from the subjective standpoint that Pharaoh himself hardened his heart:"And Pharaoh's heart was stubborn" (Exod. vii.13); and again: "And the magicians of Egypt did so with their enchantments, and Pharaoh's heart was hardened"  (Exod. vii.13); and again: "And Pharaoh's heart was stubborn; neither would he let the children of Israel go" (Exod. ix.35). And for this reason St. Paul writes: "Is there unrighteousness with God? God forbid. For He saith to Moses, I will have compassion on whom I will have compassion. So then it is not of him that willeth, nor of him that runneth, but of God that showeth mercy. For the Scripture saith unto Pharaoh, Even for this same purpose have I raised thee up, that I might show My power in thee" (Rom. ix.14-17).
Altho Pharaoh is the most conspicuous figure in this respect, yet the hardening is not confined to him alone. Of Sihon, the feared despot of Hesbon, it is written: "The Lord thy God hardened his spirit and made his heart obstinate, that He might deliver him into thine hand, as appeareth this day." (Deut.2:30) Of the allied kings of North Palestine, who under Jabin, king of Hazor, declared war against Joshua, it is written: "For it was of the Lord to harden their hearts, that they should come against Israel in battle" (Joshua xi.20).
Satan said that he tempted David to number the people (1 Chron. xxi.1); but, from 2 Sam. xxiv.1, it is evident that he did not act without divine direction and obeyed only reluctantly.
The prophet mournfully asks: "O Lord, why hast Thou made us to err from Thy ways and hardened our hearts from Thy fear?" (Isa. lxiii.17); a touching complaint which echoes the awful prophecy of his installation: "Go and tell this people, Hear ye indeed but understand not, and see ye indeed but perceive not. Make the heart of this people fat and make their heart heavy, and shut their eyes; lest they see with their eyes and hear with their ears, and understand with their hearts, and convert and be healed" (Isa. vi.9, 10).
To the objection that this is Old-Testament theology, but that such harshness is foreign to the Christian Church in which Christ has instituted the reign of Love, we reply that that Church is as old as Paradise, that in both covenants it is the same divine Speaker, and that Christ and His apostles reveal the same hardening. In Matt. xiii.14, Mark iv.12, 14, Luke viii.10, Christ largely dwells upon the fact, and states it, even for the direction of conduct, in the very words of Isaiah's inauguration prophecy, that sometimes God causes the Word to come to a man in such a way that hearing he hears not, but hardens his heart. And St. Paul addressed the same words to the Romans (Acts xxviii.26; x.8). We have already noticed his words, "To give over to a reprobate mind," and to the darkening of heart, which have the same effect as the hardening. It is remarkable that the New Testament especially presents the idea of hardening in a passive form, not as an act of the subjects themselves, but as a calamity which has come upon them as a terrible consequence of their sins. In Rom. xi.25 it reads: "For I would not, brethren, that ye should be ignorant of this mystery, that a hardening in part is happened to Israel"; in 2 Cor. iii.14: "But their minds were hardened"; in Rom. xi.7, "And the rest were hardened." So also in Mark vi.52: "Their heart was hardened"; in Acts xix.9: "But divers were hardened"; and lastly in Heb. iii.13: "But exhort one another while it is called to-day; lest any of you be hardened through the deceitfulness of sin."
With these passages before us, it is impossible to deny that the Scripture reveals God as the Author of the hardening. And he who says that the God whom he worships can not harden any man's heart, ought to see that he does not worship the God of the Scripture.
The objection that if hardening is a divine operation, then warning and admonition are vain and useless, points to another extreme. The same Scripture which says, "And whom He will He hardeneth," (Rom. ix.18) says also, "But exhort one another while it is called to-day, lest any of you be hardened." (Heb. iii.13) To both these passages we submit, bringing into captivity every thought to the obedience of the Word.
 And Paraoh's heart hardened itself" (Dutch Translation).