Tafsir Al-Jalalayn: Al-Anbiyaa, Ayah 33

And He it is Who created the night and the day and the sun and the moon each kullun the nunation of this particle stands in place of the second noun of the genitive construction that would have been al-shams ‘the sun’ or al-qamar ‘the moon’ or their subsidiaries namely al-nujūm ‘the stars’ in an orbit a circular one like a mill in the sky swimming moving with speed like a swimmer in water. In order to effect the analogy with the latter the plural person of the verb employed for rational beings is used.