Surah Al-Fajr 89:22

وَجَآءَ رَبُّكَ وَٱلْمَلَكُ صَفًّا صَفًّا

And your Lord has come and the angels, rank upon rank,

Translation: Saheeh International

Tafsir

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’

Excerpt from Tafsir al-Jalalayn, commentary on 89:22, via Quran.com. The reader has the full commentary and 9 more tafsirs.