Surah At-Takwir 81:17

وَٱلَّيْلِ إِذَا عَسْعَسَ

And by the night as it closes in

Translation: Saheeh International

Tafsir

and by the night as it approaches as it falls with its darkness or it means as it recedes;

Excerpt from Tafsir al-Jalalayn, commentary on 81:17, via Quran.com. The reader has the full commentary and 9 more tafsirs.