Abdullah bin Abbas reported,

The polytheists said, "If Muhammad is truly a prophet as he claims, then why does his Lord punish him by not sending the Quran down to him all at once? Instead, He sends down to him a verse, or two verses, or a surah at a time."So Allah sent down to His Prophet the answer to what they said, "And those who disbelieve say, 'Why was the Quran not revealed to him all at once?'" until "and most astray in way" [Furqan 25:32–34].

Azami 12909

Hasan

عن ابن عباس قال

قال المشركون: إن كان محمد كما يزعم نبيا، فلم يعذبه ربه، ألا ينزل عليه القرآن جملة واحدة، ينزل عليه الآية والآيتين والسورة؟ فأنزل الله على نبيه جواب ما قالوا: {لولا نزل عليه القرآن جملة وحدة} إلى{وأضل سبيلا}

الأعظمي 12909حسن
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Tafsir of the great Quran
Chapter
Tafsir of Surah Furqan
Section
His saying, "And those who disbelieve say, 'Why was the Quran not sent down to him all at once?' Thus, that We may strengthen your heart thereby, and We have recited it to you in slow, measured tones. And they do not come to you with any argument except that We bring you the truth and a better tafsir. Those who will be gathered on their faces to Hell, those are worst in position and most astray in path."
Numbering
Jami al-Kamil 12909 (2nd edition)
Azami 12909