Moralia in Job 500

Verse 14. — If he destroy, there is none that can build; if he shut up a man, there is none that can open. Almighty God destroys the human heart when he forsakes it, and builds it up when he fills it. For he does not destroy the human mind by warring against it, but by withdrawing from it, since it suffices for its own perdition when left to itself. Hence it often comes to pass that, when the heart of a hearer is not filled with the grace of almighty God because his sins demand it, he is admonished outwardly by the preacher in vain, for every mouth that speaks is dumb unless he who inspires the words that are heard cries out within in the heart. Hence the Prophet says:

Except the Lord build the house, they labour in vain that build it (Ps. cxxvi, 1). Hence Solomon says: Consider the works of God, that no man can amend him whom he hath despised (Eccl. vii, 14). And it is no wonder if a preacher is scarcely heard by a reprobate heart, since sometimes the Lord himself is opposed by the resisting ways of those to whom he speaks. For this is why Cain could be admonished by the divine voice yet could not be changed, because, his guilt of malice so demanding, God had already forsaken within the heart to which outwardly he was uttering words for a testimony. And it is well added: If he shut up a man, there is none that can open.

For every man, by that which he does wickedly, what else does he make for himself but a prison of his own conscience, so that the guilt of his soul may oppress him, even though no one accuse him outwardly? He who, God judging, is left in the blindness of his own malice is, as it were, shut up within himself, that he may find no place of escape, which he in no way deserves to find. For often certain men desire to come forth from their depraved deeds; but because they are weighed down by the burden of those very deeds, shut up in the prison of evil habit, they cannot come forth from themselves. And some, desiring to punish their own faults, turn into graver faults that which they reckon they are doing rightly; and it comes to pass in a wretched manner that what they suppose to be an exit they find to be a shutting-in.

Thus assuredly the reprobate Judas (Matth. xxvii, 5), when he brought death upon himself against his sin, arrived at the torments of eternal death, and repented of his sin more wickedly than he had sinned. No one resists God when he calls; no one meets him when he forsakes. Let it be said, then: If he shut up a man, there is none that can open; because, just as none withstands the bounty of him who calls, so none meets the justice of him who forsakes. To shut up, therefore, belongs to God: not to open to those shut in. Hence also it is said to Moses concerning Pharaoh: I will harden his heart (Exod. iv; vii, 3). For God is said to harden by justice when he does not soften the reprobate heart by grace. He shuts up, then, the man whom he leaves in the darkness of his own works.

For Isaac, as it were, wished to open this shutting-in for his firstborn son, when he strove by blessing to set him before his brother (Gen. xxvii, 5). But the son whom the father wished, the Lord rejected; and the one whom the Lord wished, the father blessed even against his will (Ibid., xxv, 34); so that he who had already sold his birthright to his brother for food should not receive the blessing of the firstborn, which he had abandoned out of gluttonous craving: he who, coveting earthly things, following fleeting things, desiring to inherit the blessing, was rejected. For he found no place of repentance, although he sought it with tears (Heb. xii, 17), because indeed those laments bear no fruit which strive with groaning to desire things that must perish.

Isaac therefore could not open even for his son, whom almighty God by just judgment shut up in the prison of his own malice. There follows: