Tafsir of Al-Furqan 25:32

The Reason why the Qur'an was revealed in Stages, the Refutation of the Disbelievers, and their Evil End Allah tells:

وقال الذين كفروا

And those who disbelieve say: Allah tells us about the many objections raised by the disbelievers, their stubbornness, and how they spoke of things which were none of their concern. They said:

لوﻻ نزل عليه القرآن جملة واحدة

"Why is not the Qur'an revealed to him all at once!'' meaning, why was this Qur'an, which was revealed to him, not sent down all at one time, as the previous Books, the Tawrah, Injil, Zabur and other Divine Books. Allah answered them, telling them that it was revealed in stages over twenty-three years, according to events and circumstances, and whatever rulings were needed, in order to strengthen the hearts of the believers, as He says:

وقرءانا فرقناه

And (it is) a Qur'an which We have divided (into parts)... (17:106) Allah says:

كذلك لنثبت به فوادك ورتلناه ترتيﻼ

thus, that We may strengthen your heart thereby. And We have revealed it to you gradually, in stages. Qatadah said it means: "We have explained it.'' Abdur-Rahman bin Zayd bin Aslam said it means: "We have given its interpretation.''