﴿ وَإِنَّهُۥ لَقَسَمٌۭ لَّوْ تَعْلَمُونَ عَظِيمٌ ﴾

“and, behold, this is indeed a most solemn affirmation, if you but knew it!”

And indeed it the swearing by these setting-places of stars is a tremendous oath if you only knew — if you were people of deep knowledge you would realise the magnitude of this oath.