John Calvin Commentary Psalms 65:10

"Thou waterest its furrows abundantly; Thou settlest the ridges thereof: Thou makest it soft with showers; Thou blessest the springing thereof." — Psalms 65:10 (ASV)

Thou dost saturate its furrows. Some take the verbs as being in the optative mood and construe the words as a prayer. But there can be little doubt that David still continues the theme of thanksgiving, praising God for moistening and saturating the earth with rains so that it may be fit for producing fruit.

By this he would signify to us that the whole order of things in nature shows the fatherly love of God, who condescends to care for our daily sustenance. He multiplies his expressions when speaking of a part of divine goodness, which many have wickedly and impiously disparaged. It would seem that the more insight people have in observing secondary causes in nature, the more determinedly they will stop at these causes, instead of ascending through them to God.

Philosophy ought to lead us upward to Him, the more it penetrates the mystery of His works; but this is prevented by the corruption and ingratitude of our hearts. And as those who pride themselves on their acuteness turn their eyes away from God to find the origin of rain in the air and the elements, it was all the more necessary to awaken us from such a spirit.