Commentary for Job 37:12

And he who is thus appointed.

turns around in circuits by His guidance [i.e., by the guidance] of the Omnipresent.

for their work namely, of the rains; for the work which is incumbent upon them to do, either good or evil, he is turned about with many circuits, as [the passage] that we learned (Rosh Hashanah 17b): if Israel were perfectly righteous on Rosh Hashanah so that [much] rain was decreed for them, and they should later become sinful—it would be impossible to decrease it [the amount of rain] because the decree would already have gone forth; but the Holy One, blessed be He, would let it come down out of its season and upon a land that did not require it. “And sometimes to do good”; how is this? etc.