And those who disbelieve say ‘Why has the Qur’ān not been revealed to him all at once?’ as the Torah the Gospel and the Book of Psalms were. God exalted be He says We have revealed it thus in parts it is that We may strengthen your inner-heart with it and We have arranged it in a specific order that is to say We produce it in stages one part after another gradually and deliberately in order to facilitate its comprehension and its memorisation.