﴿ وَجَآءَ رَبُّكَ وَٱلْمَلَكُ صَفًّۭا صَفًّۭا ﴾

“and [the majesty of] thy Sustainer stands revealed, as well as [the true nature of] the angels; rank upon rank?”

and your Lord that is to say His command and the angels arrive rank on rank saffan saffan is a circumstantial qualifier meaning ‘standing in rows’ or ‘made up of many ranks’