The disbelievers say, “If only the Quran had been sent down to him all at once!” ˹We have sent it˺ as such ˹in stages˺ so We may reassure your heart with it. And We have revealed it at a deliberate pace.
— Dr. Mustafa Khattab, the Clear Quran
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.1
— Saheeh International