John Calvin Commentary John 12:40

"He hath blinded their eyes, and he hardened their heart; Lest they should see with their eyes, and perceive with their heart, And should turn, And I should heal them." — John 12:40 (ASV)

He hath blinded their eyes, and hardened their heart. This passage is taken from Isaiah 6:9, where the Lord forewarns the prophet that the labor he spends in instructing will lead to no other result than to make the people worse. First, then, He says, Go, and tell this people, Hearing, hear and do not hear; as if He had said, “I send you to speak to the deaf.” He afterwards adds, Harden the heart of this people. By these words He means that He intends to make His word a punishment to the reprobate, so that it may render them more thoroughly blind, and that their blindness may be plunged in deeper darkness.

It is indeed a dreadful judgment of God when He overwhelms people with the light of doctrine in such a way as to deprive them of all understanding, and when, even by means of that which is their only light, He brings darkness upon them.

But it should be observed that it is incidental to the word of God that it blinds people; for nothing can be more inconsistent than that there should be no difference between truth and falsehood, that the bread of life should become a deadly poison, and that medicine should aggravate a disease.

But this must be ascribed to the wickedness of people, which turns life into death. It should also be observed that sometimes the Lord Himself blinds the minds of people by depriving them of judgment and understanding; sometimes by Satan and false prophets, when He maddens them by their impostures; sometimes, too, by His ministers, when the doctrine of salvation is injurious and deadly to them.

But provided that prophets labor faithfully in the work of instruction and commit the result of their labor to the Lord, even if they do not succeed as they wish, they should not give way or despair. Let them rather be satisfied with knowing that God approves of their labor, though it may be useless to others, and that even the savor of doctrine, which wicked people render deadly to themselves, is good and pleasant to God, as Paul testifies (2 Corinthians 2:15).

The heart is sometimes in Scripture used for the seat of the affections; but here, as in many other passages, it denotes what is called the intellectual part of the soul. To the same purpose Moses speaks:

God hath not given you a heart to understand,
(Deuteronomy 29:4).

Lest they should see with their eyes. Let us remember that the prophet speaks of unbelievers who had already rejected the grace of God. It is certain that all would continue to be such by nature if the Lord did not form to obedience to Him those whom He has elected.

At first, therefore, the condition of all people is equal and alike; but when reprobate people, of their own accord and by their own wickedness, have rebelled against God, they subject themselves to this vengeance, by which, being given up to a reprobate mind, they continually rush forward more and more to their own destruction.

It is their own fault, therefore, if God does not choose to convert them, because they were the cause of their own despair.

We are also briefly instructed by these words of the prophet as to what the beginning of our conversion to God is. It is when He enlightens the hearts, which must have been turned away from Him as long as they were held by the darkness of Satan; but, on the contrary, such is the power of Divine light that it attracts us to itself and forms us to the image of God.

And I should heal them. He next adds the fruit of conversion, that is, healing. By this word the prophet means the blessing of God and a prosperous condition, and likewise deliverance from all the miseries which spring from the wrath of God. Now, if this happens to the reprobate, contrary to the nature of the word, we should attend to the contrast implied in its opposite use; namely, that the purpose for which the word of God is preached is to enlighten us in the true knowledge of God, to turn us to God, and reconcile us to Him, so that we may be happy and blessed.