Surah 52. At-Tur, Ayah 24

See note [6] on {56:17-18}.

Thus Razi, explaining the selfless devotion implied in the pronoun lahum (lit., "for them" i.e., "of their own").

Maknun: well-guarded, kept close, concealed from exposure: the beautiful nacreous lustre of Pearls is disfigured by exposure to gases, vapours, or acids; when not actually in use they are best kept in closed caskets, guarded from deteriorating agencies.