Surah Al-Anbya 21:49

ٱلَّذِينَ يَخْشَوْنَ رَبَّهُم بِٱلْغَيْبِ وَهُم مِّنَ ٱلسَّاعَةِ مُشْفِقُونَ

Who fear their Lord unseen, while they are of the Hour apprehensive.

Translation: Saheeh International

Tafsir

those who fear their Lord in concealment from people that is when they are in seclusion from them and who on account of the Hour that is on account of its terrors are apprehensive fearful.

Excerpt from Tafsir al-Jalalayn, commentary on 21:49, via Quran.com. The reader has the full commentary and 9 more tafsirs.