Manazil are not a part
of the original presentation of the Qur’an. Like parahs, they were added later.
But it seems that manazil were added earlier than parahs. In both cases, the
idea is to enable a regular reader of the Qur’an to have clear targets to
achieve each day. While in the earlier days, many pious believers used to
complete recitation of the entire Qur’an in one week, the later people set forth
for themselves the target of one month for completing the task. Manazil help in
completing the first target and parahs help in achieving the second. In neither
case there is any indication from the Prophet (sws) that such divisions should
be introduced in the Qur’an.
The only units given by the
Prophet (sws) are ayah and surah. Also, the existing sequence is the same as
given to us by the Prophet (sws).