فَسَجَدَ الْمَلَائِكَةُ كُلُّهُمْ أَجْمَعُونَ
“So the angels prostrated, all of them together.” (Al-Hijr 15:30)
The noun al-malaʾikah refers to the angels. It is followed by the emphatic expressions kulluhum (“all of them”) and ajmaʿun (“together, every one”). Together the added words make the intended comprehensive reference emphatic.
The key to mufassar is that the statement itself provides additional clarification, thereby closing off interpretive doubts that a less explicit wording might leave open.