The Surah takes its name from the word wal-lail with which it opens.
Its subject matter so closely resembles that of Surah Ash-Shams that each Surah seems to be an explanation of the other. It is one and the same thing which has been explained in Surah Ash-Shams in one way and in this Surah in another. This indicates ...
Its theme is to distinguish between the two different ways of life and to explain the contrast between their ultimate ends and results. In view of the subject matter this Surah consists of two parts, the first part consisting of vv. 1-11 and the second of vv. 12-21....