وَقَالَ الَّذِيْنَ كَفَرُوْا لَوْلَا نُزِّلَ عَلَيْہِ الْقُرْاٰنُ جُمْلَۃً وَّاحِدَۃً۰ۚۛ كَذٰلِكَ۰ۚۛ لِنُثَبِّتَ بِہٖ فُؤَادَكَ وَرَتَّلْنٰہُ تَرْتِيْلًا۳۲
Waqala allatheena kafaroo lawla nuzzila AAalayhi alquranu jumlatan wahidatan kathalika linuthabbita bihi fuadaka warattalnahu tarteelan
The unbelievers say: "Why was the whole Qur'an not sent down all at once to him?" It was sent thus that We may keep your heart resolute. So We enunciated it by steps and distinctly.