John Calvin Commentary Malachi 3:11

"And I will rebuke the devourer for your sakes, and he shall not destroy the fruits of your ground; neither shall your vine cast its fruit before the time in the field, saith Jehovah of hosts." — Malachi 3:11 (ASV)

God now again confirms the truth that He would not be bountiful to them in only one way. He might indeed distribute our food to us daily, as we know He fed His people in this way in the wilderness. But His will is that the seed should rot in the earth, then germinate, and in time grow, until it shoots into ears of corn. However, it is still in considerable danger; indeed, the corn is subject to many harmful things before it is gathered into the granary, for locusts, worms, mildew, and other things may destroy it.

Therefore, to demonstrate His kindness to mankind, God here enumerates the ways and means by which food is preserved. For it would not be enough for the seed to germinate and for there to be signs of a large yield, with the ears of corn being fine and abundant; it is also necessary that the ears of corn themselves be preserved from above before they ripen. On the one hand, beetles, locusts, worms, and other grubs may suddenly creep in and devour the corn in the field. On the other hand, as I have said, storms, hail, mildew, and other such blights may prove ruinous to the corn.

Thus, God shows here that He takes constant care of us. Every day and every night, He fulfills the role of a good and careful head of a household, who always watches out for its well-being.

In the word devourer, I include all the destructive forces to which we see that corn is subject. God therefore says, he shall not destroy the fruit of the earth; nor bereaved shall be the vine for you in the fields. The verb שכל, shecal, properly means to bereave or to deprive. But as this rendering, “bereaved shall not be vine,” would be harsh, some have translated the words as follows: “Miscarry shall not vine,” which I do not disapprove. Miscarry then shall not the vine for you in the fields, says Jehovah of hosts.