Qutaybah b. Saʿīd > Ibn Abū ʿAdī > Dāwud / Ibn Abū Hind > ʿIkrimah > Ibn ʿAbbās

"The Qur'an was revealed in Ramadan on the Night of Decree, and it was in the lowest heaven. Whenever Allah intended to bring about something, He would send it down. It was revealed over a period of twenty years, between its beginning and its end."

أَخْبَرَنَا قُتَيْبَةُ بْنُ سَعِيدٍ قَالَ حَدَّثَنَا ابْنُ أَبِي عَدِيٍّ عَنْ دَاوُدَ وَهُوَ ابْنُ أَبِي هِنْدَ عَنْ عِكْرِمَةَ عَنِ ابْنِ عَبَّاسٍ قَالَ

«نَزَلَ الْقُرْآنُ فِي رَمَضَانَ لَيْلَةَ الْقَدْرِ فَكَانَ فِي السَّمَاءِ الدُّنْيَا فَكَانَ إِذَا أَرَادَ اللهُ أَنْ يُحْدِثَ شَيْئًا نَزَّلَ فَكَانَ بَيْنَ أَوَّلِهِ وَآخِرِهِ عِشْرِينَ سَنَةً»