فَسَجَدَ الْمَلَائِكَةُ كُلُّهُمْ أَجْمَعُونَ
So all the angels prostrated, every one of them together.
The noun “the angels” already conveys generality, yet one could initially ask whether a member of the class is excepted. Kulluhum expressly includes all members and closes off specification. Ajmaʿūn adds emphatic comprehensiveness in their action.
The wording itself therefore supplies the clarification characteristic of mufassar. First comes a general class; then emphatic inclusion removes a possible exception; further emphasis strengthens the completeness of the reported act.