Al-Isra' - ১৭:১০৬

وَقُرْآناً فَرَقْنَاهُ لِتَقْرَأَهُ عَلَى النَّاسِ عَلَى مُكْثٍ وَنَزَّلْنَاهُ تَنزِيلاً
[17:106]
And it is a Quran which We have revealed in portions so that you may read it to the people by slow degrees, and We have revealed it, revealing in portions.
(It is) a Qur'an which We have divided (into parts from time to time), in order that thou mightest recite it to men at intervals: We have revealed it by stages.
And (it is) a Qur'an that We have divided, that thou mayst recite it unto mankind at intervals, and We have revealed it by (successive) revelation.