John Calvin Commentary Jeremiah 2:12

"Be astonished, O ye heavens, at this, and be horribly afraid, be ye very desolate, saith Jehovah." — Jeremiah 2:12 (ASV)

When the Prophet saw that he had to deal with men who were completely dull-minded, almost entirely lacking reason, he turned to address the heavens. This is a common way of speaking for the Prophets—they address the heaven and the earth, which have no understanding themselves, and ignore men endowed with reason and knowledge. This they usually did in hopeless cases, when they found no willingness to learn.

So now the Prophet bids the heavens to be astonished, to be terrified, and to be reduced, as it were, to desolation; as if he had said, “This is a wonder that almost confounds the whole order of nature; it is as if we were to see heaven and earth mixed together.” We now therefore perceive the Prophet's meaning: for by this portrayal he intended to show how detestable the impiety of the people was, since the heavens, though lacking reason, ought rightly to dread such a monstrous thing.

Regarding the words, some translate them, “Be desolate, you heavens,” and then repeat the same. But as שמם shemem means to be astonished, the translation I have given suits the present passage better: “Be astonished, you heavens, for this,” and then, “be you terrified and dried up”; for חרב chareb signifies to become dry, and sometimes, to be reduced to solitude or a wasteland. It then continues:—