The Wisdom in respect to the Qur’aan being revealed in instalments
Allah Ta’Aalaa has explained the Hikmah (wisdom) for the revelation of the Qur’aan in instalments and not all at once in two Aayah:
a) The First Aayah:
And those who disbelieve say: "Why was the Qur'an not revealed to him all at once?" Thus [it is] that We may strengthen thereby your heart. And We have spaced it distinctly (Al-Furqaan 32).
b) The Second Aayah:
And a Qur'an which We have divided (into parts), in order that you might recite it to men at intervals. And We have revealed it by stages (Al-Israa’ 106).
These two Aayah indicate that the Hikmah (wisdom) for the Qur’aan to have been revealed in parts and not all at once are:
1) To strengthen and consolidate the heart of the Messenger of Allah (saw) through the revelation of the Qur’aan in parts throughout the mission of Prophethood. He had been exposed to harm and denial from his people whilst he carried the Da’wah to them and so the Wahi that descended at different times was his greatest support and assistance making him feel that Allah Ta’Aalaa was always with him. That consecutive connection over periods or intervals strengthened his determination and helped him to bear what he faced in terms of hardship and obstacles and to continue the Da’wah.