He said, “That is, their circling.”

Bandah narrated to us; my father narrated to us; ʿUbayd Allāh ibn ʿĀʾishah narrated to us; ʿAbd al-Wāḥid ibn Ziyād narrated to us; Abū Rūq said: I heard al-Ḍaḥḥāk, concerning the verse, “each one is swimming along in its orbit” (Q 36:40), say, “It revolves and moves on.”

My father narrated to us; Masrūq ibn al-Marzbān narrated to us; Yaḥyā ibn Abī Zāʾidah narrated to us; Warqāʾ from Ibn Abī Najīḥ, from Mujāhid on the same verse: “The falak is like the iron pin of a millstone”—meaning the pivot, the upright spindle that is also called a ḥusbān.

Ibn ʿAlī al-Ḥusayn ibn Ḥunayd narrated to us; Abū Bakr ibn Abī Shaybah narrated to us; Marwān ibn Muʿāwiyah narrated to us; from Juwaybir, from al-Ḍaḥḥāk regarding “in an orbit they swim” (Q 36:40): “Al-falak signifies speed and movement in a circle, and yasbaḥūn means ‘they are in motion.’” In other words, the word falak conveys both circularity and rapid movement, just like the turning of a spindle’s whorl or the rotation of a millstone.

He also narrated—my father narrated to us; Abū Ṣāliḥ narrated to us; Muʿāwiyah ibn Ṣāliḥ told me—from ʿAlī ibn Abī Ṭalḥah, from Ibn ʿAbbās—on the phrase “in a falak”: he said, “a revolution,” and on “they swim,” he said, “that is, they run.”

Iyās ibn Muʿāwiyah said, “The sky above the earth is like a dome.”

The discussion of this matter, along with its proofs from the Qur’an and the Sunnah, has been elaborated elsewhere.

In Arabic, the word falak inherently denotes roundness. Al-Jawharī says: “The whorl of a spindle (falakah) was so named because of its circular shape, and a falakah is a section of land or …”