Surah 44. Ad-Dukhan, Ayah 3

I.e., the night on which the revelation of the Qur'an began: see surah {97}.

The revelation of the Qur'an is but a continuation and, indeed, the climax of all divine revelation which has been going on since the very dawn of human consciousness. Its innermost purpose has always been the warning extended by God to man not to abandon himself to mere material ambitions and pursuits and, thus, to lose sight of spiritual values.

 The revelation of the Quran started on the 27 th  night of Ramaḍân—the 9 th  month of the Islamic calendar (see 97:1 and 2:185)

Usually taken to be a night in the month of Ramadhan, say the 23rd, 25th, or 27th night of that month. It is referred to as the Night of Power in xcvii. 1-2. See also ii. 185. But perhaps we need not fix it literally by the calendar. The night that a Message descends from Allah is indeed a blessed night like a day of rain for a parched land.