وَقَالَ And said ٱلَّذِينَ those who كَفَرُوا۟ disbelieve لَوْلَا Why not نُزِّلَ was revealed عَلَيْهِ to him ٱلْقُرْءَانُ the Quran جُمْلَةًۭ all at once وَٰحِدَةًۭ ۚ all at once كَذَٰلِكَ Thus لِنُثَبِّتَ that We may strengthen بِهِۦ thereby فُؤَادَكَ ۖ your heart وَرَتَّلْنَـٰهُ and We have recited it تَرْتِيلًۭا (with distinct) recitation ٣٢
And those who disbelieve say, "Why was the Qur’ān not revealed to him all at once?" Thus [it is] that We may strengthen thereby your heart. And We have spaced it distinctly.
— Come To Light