Tafsir of Al-Isra 17:106

وقرآنا فرقناه

And (it is) a Qur'an which We have divided, The word translated here as "We have divided'' may be read in two ways. If it is read as "Faraqnahu'', with no Shaddah, the meaning is: `We have made it depart from Al-Lawh Al-Mahfuz to Bayt Al-`Izzah in the lowest heaven, then it was revealed in stages to the Messenger of Allah, according to events, over a period of twenty-three years.' This was narrated by Ikrimah from Ibn Abbas. It was also narrated that Ibn Abbas read it as "Farraqnahu'', with a Shaddah, meaning, `We revealed it Ayah by Ayah, and have explained it and made it clear.' Hence Allah says:

لتقرأه على الناس

in order that you might recite it to men, meaning, convey it to the people and recite it to them,

على مكث

at intervals. meaning slowly.

ونزلناه تنزيﻼ

And We have revealed it by stages. means, little by little