ייִדישער מחשבֿה אויף תהילים 89:28

God placed them in the expanse of the heaven – The difference of opinion between the Sages of Israel and the Greek scholars, regarding whether the heavenly sphere is fixed in its place and the stars and constellations move in their orbits, or the stars and constellations are fixed in their positions and the heavenly sphere moves, has existed from the era of the Tannaim, as recorded in Tractate Pesachim.²⁶Pesachim 94b. See page 40 above. The view of our Sages is that the heavenly sphere is fixed and the stars and constellations move…. This conception is supported by the narrative that states first, “and God made the two great luminaries,” and only afterwards, “God placed them in the expanse of the heaven.” It appears from this passage that the luminaries are a unique creation and not merely part of the heavens. To explain: Were one to say that the luminary moves in its orbit and the heavenly sphere is fixed, it is understandable that the luminary is a separate entity from the heavens, and revolves on the surface of the heavens. A parallel to this exists with regard to the creation of man, concerning which it is stated,²⁷Bereishis 2:7. “God the Lord formed man,” and only afterwards, “God the Lord planted a garden… and placed man there.”²⁸Ibid. 2:8. I.e., just as man was first created and then placed in a different location, the moon was first created and then placed into its orbit. If, by contrast, one would postulate that the luminary was fixed in the heavens and the heavenly sphere revolved, the luminaries would be part of the essence of the heavens. Otherwise, were one to postulate that the luminaries were separate entities implanted into the heavenly sphere, as it were, the substance that previously existed there would be nullified. That theory runs contrary to logic.²⁹According to this theory, the luminaries would be displacing other matter. Instead, one would be forced to say that the luminary is part of the sphere, it is just that God in the power of His wisdom made that portion of the heavenly sphere luminous. If that is the intent, the sequence “He made the two great luminaries” and only afterwards “God placed them in the expanse of the heaven,” is problematic…. “Placing” could be interpreted as distinguishing them and granting them honor, as in the verse,³⁰Shmos 6:1. “I placed you as a judge for Pharaoh” and “I will place him as prominent.”³¹Tehillim 89:28.…

On this verse, there is a relevant passage from the Midrash:³²Bereishis Rabbah 6:8. “How do the spheres of the sun and the moon set?... Rabbi Shimon bar Yochai said: ‘We do not know whether they fly through the air, glide in the heaven, or proceed in their usual manner. It is an exceedingly difficult matter, and no created being can fathom it.’”… It is possible to explain that “flying” refers to proceeding at an exceedingly fast pace. “Gliding” also reflects swift progress, but not as fast as “flying.” An object glides rapidly because the air does not impede its progress to the same degree as an entity of substance which holds back one who runs on it. One who “proceeds in his usual manner” does not move quickly. All of these three approaches, however, follow the approach of our Sages, that the stars revolve and the heavenly sphere remains fixed in place.