John Calvin Commentary Psalms 129:7

"Wherewith the reaper filleth not his hand, Nor he that bindeth sheaves his bosom." — Psalms 129:7 (ASV)

With which the mower has not filled his hand. We have here an additional confirmation of the truth that although the wicked rise high or elevate themselves, and form an extravagant opinion of their own importance, yet they remain mere grass, not producing any good fruit, nor reaching ripeness, but swelling only with a fresh appearance.

To make this obvious, the Psalmist contrasts them with fruit-bearing plants, which in valleys and low grounds produce fruit for humans. In short, he affirms that they deserve to be hated or despised by all, while, in contrast, everyone who passes by the corn fields usually blesses them and prays for the harvest.

Furthermore, he has borrowed this illustration for his teaching from ordinary life. We are taught that whenever there is a hopeful prospect of a good harvest, we ought to implore God, whose special role it is to give fertility to the earth, that He would bring His blessing to full fruition.

And considering that the fruits of the earth are exposed to so many hazards, it is certainly strange that we are not stirred up to engage in prayer, given their absolute necessity for humans and animals. Nor does the Psalmist, in speaking of passersby blessing the reapers, speak exclusively of the children of God, who are truly taught by His word that the fruitfulness of the earth is due to His goodness; but he also includes worldly people, in whom the same knowledge is naturally implanted.

In conclusion, if we not only dwell in the Church of the Lord but also strive to have a place among her genuine citizens, we will be able to fearlessly despise all the fierce might of our enemies. For although they may flourish and make a great outward show for a time, they are only barren grass, on which heaven’s curse rests.