وَ الَّیۡلِ اِذَا سَجٰی ۙ﴿۲﴾

And by oath of the night when it covers,

Tafsir al-Qurtubi                                                                                                                         تفسیر القرطبی                                                    

قَالَ قَتَادَةُ وَمُقَاتِلٌ وَجَعْفَرُ الصَّادِقُ: أَقْسَمَ بِالضُّحَى الَّذِي كَلَّمَ اللَّهُ فِيهِ مُوسَى، وَبِلَيْلَةِ الْمِعْرَاجِ.

Sayyiduna Qatadah, Sayyiduna Muqatil and Imam Ja’fer al-Sadiq – may Allah be pleased with them – said:  Allah Almighty took the oath of that day in which He had spoken to Sayyiduna Moosa – peace be upon him – and the night signifies the night of Me’raj.

Tafsir Qurtubi (Al-Jame’ Li Ahkaam al-Quran) Imam Shamsuddin Muhammad ibn Ahmad al-Qurtubi t D. 671 A.H.