Usool At-tafseer by Shu‘bah ibn al-Hajjaaj, Sufyaan ibn ‘Uyaynah and it was translated by Dr. M. Abdul Haq Ansari

The process of education depends on the following two basic principles: (a) taking into account the mental level of the students, and (b) developing their mental, spiritual and physical abilities with material which guides their thought processes in the correct direction. Both of these important principles have been carefully taken into consideration by the revelation of the Qur’aan in segments.

Gradation of legislation took into account the level of the Muslim community during its various stages of development. The revelation of corrections and answers at the time when they were most needed trained, developed and guided the mental, spiritual and physical faculties in the right direction.

The question which naturally arises here is why the earlier books of revelation were revealed as a whole. The answer to this question lies in the role of the earlier books and the history of prophethood. The earlier books were sent for short periods in human history and were directed to specific nations or tribes.

They contained principles which were not time or situation oriented and could be revealed all at once, at the beginning of a mission or at any point during it. It should also be noted that the earlier books were not in themselves miracles, whereas in the case of the Last Prophet (ﷺ), it was the major miracle given to him, for, as was mentioned earlier, the segmentation of the revelation combined with the consistency of style was a proof of its divine origin. Also, the earlier prophets were both preceded and followed by other prophets, so each prophet and his book represented a segment of the overall revelation. Thus, the gradation in legislation took place from prophet to prophet. Prophet Muhammad (ﷺ) was the last of the prophets and his book of revelation contained the essential messages of all previous books. Thus, his followers had to be properly prepared to carry the final message to the world. As such, the gradation in legislation had to take place within the message itself.