Al-Layl
This sūrah was revealed in Mecca and consists of 21 verses. The chapter’s objective is to warn. It does this by pointing out the differences between people’s striving. Some people spend their wealth [in the way of God], are conscious of God, and affirm what is good. Thus God will provide them with eternal happiness in the next life. Others are stingy, chase after wealth, and belie what is good. Thus, God will lead them to misery in the hereafter. The chapter places a special emphasis on financial charity [in the way of God].
The sūrah could have been revealed either in Mecca or in Medina; its contents are appropriate for either.
This is the ʿAllāmah's introduction to the sūrah, from the opening of the commentary.