John Calvin Commentary Isaiah 40:7

"The grass withereth, the flower fadeth, because the breath of Jehovah bloweth upon it; surely the people is grass." — Isaiah 40:7 (ASV)

The grass is withered. This might be understood to relate to the beauty of the fields, which is spoiled by a single gust of wind, as it is said (Psalms 103:16), As soon as the wind passeth over it, it is gone. For we know that the wind is called “the Spirit of God” in other passages. But I am more inclined to think that the metaphor is adapted to the present subject, for otherwise its application would be somewhat obscure. The Prophet therefore explains what object he has in view by saying that men, with all their glory, are nothing else than grass; that is, because the Spirit of God will quickly carry them away by a single breath.

Because the Spirit of Jehovah hath blown upon it. The meaning may be explained this way: “However illustrious are the gifts with which men are endowed, yet as soon as the Spirit of God shall blow upon them, they shall feel that they are nothing.” For the false confidence with which they intoxicate themselves springs from this source: they do not appear before God but, to indulge freely in flattering themselves, creep into places of concealment.

So that they may no longer deceive themselves with a foolish delight in falsehood, the Prophet drags them into the presence of God. He admits that they apparently flourish when they have been withdrawn from God; but as soon as the Lord has breathed upon them, all their strength and beauty perish and decay.

But it may be thought that he assigns to “the Spirit of God” an office that is greatly at variance with his nature, for it belongs to him to renew by his power the face of the earth (Psalms 104:30). On the other hand, if the Lord withdraws his Spirit, all is reduced to nothing. Here Isaiah asserts what is exceedingly different and appears to contradict David.

But there is no absurdity in saying that all things are renewed by the power of the Spirit, and also that what formerly appeared to be something is reduced to nothing. This is because we are nothing apart from God. For us to begin to be something in him, we must first be convinced and made to understand thoroughly that we are vanity. Therefore, the Lord breathes upon us, so that we may know that of ourselves we are nothing.

Surely the people is grass. The Prophet added this so that all might know that he was not speaking of foreigners, but of that people who gloried in the name of God. For the Jews might have thought that they were more excellent and held a higher rank than other people, and that on this account they ought to be exempted from the common lot.

He therefore addresses them expressly and by name, so that they may not claim anything for themselves above others. It is as if he had said that they would act wisely if, through a conviction of their poverty, they should cast away all confidence in themselves. In a word, the Prophet, after having mentioned consolation, shows how people must be prepared to receive it, for they are not capable of it until they have first been reduced to nothing.

Our hardness must therefore be softened, our haughtiness must be cast down and laid low, our boasting must be put to shame, and our hearts must be subdued and humbled, if we wish to receive beneficially the consolations that the prophets bring to us by the command of God.