الَّذِينَ يَخْشَوْنَ رَبَّهُم بِالْغَيْبِ وَهُم مِّنَ السَّاعَةِ مُشْفِقُونَ
—those who fear their Lord in secret, and who are apprehensive of the Hour.
Agha Ali Puya Commentary
Commentary on Quran 21:49
[Pooya/Ali Commentary 21:49] This verse refers to the muttaqin mentioned in the preceding verse who fear Allah and keep themselves always ready for the hour of reckoning. Refer to al Baqarah: 2, 177 and Ali Imran: 138.