وَقَالَ ٱلَّذِينَ كَفَرُواْ لَوْلَا نُزِّلَ عَلَيْهِ ٱلْقُرْءَانُ جُمْلَةً وَٲحِدَةًۚ كَذَٲلِكَ لِنُثَبِّتَ بِهِۦ فُؤَادَكَۖ وَرَتَّلْنَـٰهُ تَرْتِيلاً ٣٢
And those who disbelieve say: Why is the Qur'an not revealed unto him all at once? (It is revealed) thus that We may strengthen thy heart therewith; and We have arranged it in right order.