Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
quran:92:1 – In the name of Allah, the Entirely Merciful, the Especially Merciful.

By the night when it covers  

By the night as it enshrouds, with its darkness all that is between the heaven and the earth,
القرآن:٩٢:١ – بِسْمِ اللَّهِ الرَّحْمَٰنِ الرَّحِيمِ

وَاللَّيْلِ إِذَا يَغْشَىٰ  

{والليل إذا يغشى} بظلمته كل ما بين السماء والأرض.

See similar narrations below:

Collected by Qurʾān
quran:91:4 –

And ˹by˺ the night when it covers it  

and ˹by˺ the night when it enshrouds her, covering her up with its darkness (idhā, ‘when’, in all three instances is an absolute adverbial, operated by the verbal action of the oath).
القرآن:٩١:٤ –

وَاللَّيْلِ إِذَا يَغْشَاهَا  

{والليل إذا يغشاها} يغطيها بظلمته وإذا في الثلاثة لمجرد الظرفية والعامل فيها فعل القسم.