Allah (swt) mentions the night many times in the Holy Qur’an. Even that there is a Surah called (the Night).

It is known that the night is the time of establishing worship and prayers as when the night covers the universe, calmness is revealed. Allah (swt) says in other verses:

{وَاللَّيْلِ إِذَا سَجَىٰ}

(And [by] the night when it covers with darkness) (Ad-Duha: 2)

{وَاللَّيْلِ إِذَا يَسْرِ}

(And [by] the night when it passes) (Al-Fajr: 4)

The darkness of the night covers the universe. It approaches slowly and spreads quietly its darkness, and gradually covers the daylight, and here Allah (swt) mentions something else that characterizes the night in addition to that it covers and passes:

 وَاللَّيْلِ وَمَا وَسَقَ

(And [by] the night and what it envelops (17))

وَسَقَ (envelops): Means to join the thing together.

At night, the trees, mountains, seas, and land are covered with darkness.