This night is mentioned in Surah Fajr
Hadhrat Ismail Haqqi (May Allah shower His mercy on him) writes the various interpretations of verse no. 4 in Tafseer Ruh Al Bayan:
Translation:……….If this meaning is taken generally, it might mean any night and anyone who travels in the night. The second interpretation is that this doesn’t mean any night, but means a special night and that is the 27th night of Rajab and the traveler is not any traveler, but it means the one who travels in the spiritual realms for the proximity of Allah Most High and to see him, the Holy Prophet (Sallallahu alaihi wa sallam). As per this interpretation, the translation of this verse will be: By the 27th night of Rajab! In which the Holy Prophet (Sallallahu alaihi wa sallam) traveled the spiritual realms.
Hadhrat Ismail (May Allah shower His mercy on him) writes further:
Translation: The wisdom behind swearing by the 27th night of Rajab is that Allah Most High took His most special worshipper, the Holy Prophet (Sallallahu alaihi wa sallam) on a tour and through this, this night became more distinguished than all other nights. This is a valued night, a night of eminence, closeness and union and vision and of ultimate beauty. (Tafseer Ruh Al Bayan, Surah Fajr, 4)
There are no two opinions that when Allah Most High mentions a night, it shows the superiority and excellence of that night. Thus, the night is spent in worship and prayer to gain the special blessings of that night and to fill one’s coffers with the mercy that descends that night.
Abul Hasanaat Islamic Research Center 