John Calvin Commentary Isaiah 30:23

"And he will give the rain for thy seed, wherewith thou shalt sow the ground; and bread of the increase of the ground, and it shall be fat and plenteous. In that day shall thy cattle feed in large pastures;" — Isaiah 30:23 (ASV)

Then will he give rain to your seed. From the fruit, he again shows how desirable it is to be converted to God. For the fruit of repentance is that he receives converted persons into favor and bestows his blessing on them, so that they lack nothing but, on the contrary, are loaded with every kind of blessing. As troubles and distresses proceed from the wrath of God, whom we provoke by our crimes, so, when he is pacified, everything goes on prosperously with us, and we obtain every sort of kindness, as the Law more fully testifies (Leviticus 26:3–13; Deuteronomy 28:3–14).

Previously, he had spoken of “rain,” from which they were led to expect an abundant supply of food. But because he did not begin by addressing earthly and fading blessings in a particular sequence, he now adds to doctrine—which is spiritual nourishment—those things pertaining to the use of this corruptible life. For, although godliness has the promise of the present life as well as of that which is to come (1 Timothy 4:8), yet first of all it aims at heaven (Matthew 6:33).

From this, let us also learn that it is in vain for people to toil in cultivating their fields if the Lord does not send rain from heaven. Our labors must be watered by him, and he must give the increase; otherwise, they will be of no service. Yet we must not expect rain except from the blessing of God; and if we receive abundant produce, we should give him the glory.

From this, learn also that we will lack nothing and will obtain very abundant fruits of our labors if we are converted to God. It is our own fault that we often suffer poverty and want, because by our wickedness we drive away the blessing of God from us.

Let us not, therefore, ascribe barrenness and famine to any causes other than our own fault. For it is not that the earth is incapable of providing support and nourishment for such a great multitude of people. Instead, it is by our iniquities and transgressions that we shut the bosom of the earth. Otherwise, it would be opened to us and would abundantly yield fruits of every kind, allowing us to lead a prosperous and happy life.

And your cattle shall feed. What he now adds about the “cattle” greatly magnifies the grace of God. For if his kindness overflows even to mute cattle (Psalms 36:6), how much more to human beings whom he created after his image (Genesis 1:27). But we need not wonder if animals, which were created for human use, suffer hunger along with their masters and share in the bestowal of favor when God is reconciled to human beings.