Surah 89. Al-Fajr, Ayah 4

An allusion to the night of spiritual darkness which is bound to "run its course" - i.e., to disappear - as soon as man becomes truly conscious of God.

That is, the last part of the night, just before full day-light. Note the gradations: first, the turn of the night, when just the first rays of daylight break through; secondly, the social and institutional rites of religion, like those during the ten nights of Pilgrimage; thirdly, when the usual contrast between the Here and Hereafter vanishes, and we can see heaven even here; and lastly, when this world vanishes, the full light of Day arrives, and we see Reality face to face.