(Annajm) 53 : 1
بِسْمِ اللَّهِ الرَّحْمَٰنِ الرَّحِيمِ وَالنَّجْمِ إِذَا هَوَىٰ
And the star, when it sets.
By swearing by the visible phenomenon of the star and thereby the dawn appearing, Allah says.