John Calvin Commentary Psalms 147:15

"He sendeth out his commandment upon earth; His word runneth very swiftly." — Psalms 147:15 (ASV)

While he sends forth, and so forth. He again touches upon some instances of the operation of God, everywhere to be seen in the system of nature. And as the changes that take place in the air and on the earth, and which should be considered evidences of his power, may perhaps be regarded by the world as the effect of chance, the Psalmist, before proceeding to speak of the snow, hoar frost, and ice, expressly declares that the earth is governed by his power and control.

The sending forth of his word is nothing else than the secret influence by which he regulates and governs all things, for without his orders and appointment no movement could take place among the elements, nor could they be carried, now one way and now another, by their own spontaneous impulse without his prior secret decree.

He says that his word runneth quickly, because, once God has indicated his will, all things concur to carry it into effect. If we do not hold firmly to this principle, however acutely we may investigate second causes, all our insight will come to nothing. Thus, Aristotle, for example, has shown such ingenuity on the subject of meteors that he discusses their natural causes most exactly, while he omits the main point of all, on which even a child, at least one having any religion, surpasses him.

One must have little discernment who, in the sudden snows and hoar frosts, does not perceive how quickly the word of God runs. If, then, we are to avoid a senseless natural philosophy, we must always start with this principle: that everything in nature depends upon the will of God, and that the whole course of nature is only the prompt execution of his orders.

When the waters congeal, when the hail spreads through the air, and hoar frosts darken the sky, surely we have proof of how effective his word is. But if all these wonders produce no effect on most people, at least the piercing cold that benumbs our bodies should compel us to recognize the power of God.

When the heat of the sun scorches us in summer, and again, when winter follows, all things are bound up, such a change as this, which must have appeared incredible if we were not accustomed to it, cries out loudly that there is a being who reigns above.