Tafseer Ibn Kathir of YAA SIIN [40]

لَا الشَّمْسُ يَنبَغِي لَهَا أَن تُدْرِكَ الْقَمَرَ وَلَا اللَّيْلُ سَابِقُ النَّهَارِ وَكُلٌّ فِي فَلَكٍ يَسْبَحُونَ

It is not allowable for the sun to reach the moon, nor does the night overtake the day, but each, in an orbit, is swimming.