John Calvin Commentary Jeremiah 23:29

"Is not my word like fire? saith Jehovah; and like a hammer that breaketh the rock in pieces?" — Jeremiah 23:29 (ASV)

He confirms what he said about the chaff and the wheat, but in different words. It was a fitting comparison when Jeremiah compared God’s word to wheat, and the figments of men to chaff. But as the Jews, through their ingratitude, rendered the word of God ineffective, so it did not become a spiritual support for them; the Prophet says that it would become like a fire and like a hammer.

It was as if he had said that even though the Jews were devoid of judgment, having become hardened in their wickedness, yet the word of God could not be rendered void, nor could its power be taken away. For as Paul says, If it is not the odor of life unto life, it is the odor of death unto death to those who perish, (2 Corinthians 2:16).

And so also the same Apostle says in another place, that God’s servants had vengeance in their power, for they bear the spiritual sword, to cast down every height that exalts itself against Christ; but he adds, After the obedience of the faithful had been completed. (2 Corinthians 10:6).

The first and, as it were, the natural use of God’s word is to bring salvation to men, and hence it is called food; but it turns into poison for the reprobate, and this is the reason for such great diversity.

He said, first, that God’s word was wheat, because souls are nourished by it to a celestial life, and nothing can be more delightful than this comparison. But now he declares it to be fire and a hammer.

There is in these terms some appearance of contradiction, but a distinction is to be made regarding the hearers. For those who reverently embrace the word of God, as is fitting for them, and with genuine docility of faith, find it to be food for them; but the ungodly, as they are unworthy of such a benefit, find it to be far otherwise.

For the word which is in itself life-giving is changed into fire, which consumes and devours them; and it also becomes a hammer to break, tear them in pieces, and destroy them.

The meaning of the whole is that God’s word always retains its own dignity. For if it happens to be despised by men, it still cannot be deprived of its vigor and efficacy; if it is not wholesome for food, it will be like fire or like a hammer.

Thus, these two comparisons belong to the wicked. For God’s word has another sense when called fire with reference to the faithful, namely because it dries up and consumes the lusts of the flesh, just as silver and gold are purified by fire.

Hence the word of God is properly and fittingly called fire, even with regard to the faithful; but not a devouring fire, rather a refining fire.

But when it comes to the reprobate, it must necessarily destroy them, for they do not receive the grace that it offers them.

It may also be called a hammer, for it subdues the depraved affections of the flesh and those things that are opposed to God, even in the elect; but it does not break the elect, for they allow themselves to be subdued by it.

But this hammer is said to break the stone or the rock because the reprobate will not listen to correction; they must, therefore, necessarily be broken and destroyed. For this reason Paul also, while speaking of the refractory, says, Let him who is ignorant be ignorant. (1 Corinthians 14:38).

For by these words he means that they will at last discover how great is the hardness of that word with which they dare to contend through the perverseness of their heart.

But that passage which I quoted before well explains what is said here by Jeremiah: namely, that truth in itself is wholesome, but that it turns into an odor of death unto death for those who perish (2 Corinthians 2:16). Paul, indeed, speaks of the Gospel, but this may also be applied to the Law.