(radhiyallahu anhu), Soorahs
were not placed in sequence, rather each Soorah was written separately. They wrote down
all the Soorahs in their proper sequence in a single copy.(Mustadrak)
in order that it
could be read both 
and 
, because both readings are correct.(Manaahilul Irfaan)
(radhiyallahu anhu) had accomplished the preparation of five copies, but Aboo Haatim Sijistaani
says that a total of seven copies were prepared. Out of these, one was sent to Makkah, one to Syria, one to Yaman, one to Bahrain, one to Basra and one to Kufa, and one was
preserved in Madeenah. (radhiyallahu anhu).
But along with it, as a matter of added precaution, they adopted exactly the same method
that was employed during the time of Aboo Bakr (radhiyallahu anhu). Consequently, assorted copies
of texts committed into writing during the days of the Prophet 
(sallallahu alayhi wasallam)
which were preserved by different Companions were recalled once again, and it was, by yet
another collation with these, that the new copies were prepared. This time, a separately
written verse of Soorah Ahzaab was found with Khuzaymah Ibne Thaabit Ansaari (radhiyallahu anhu)
only. As we have explained earlier, it does not mean that nobody else remembered this
verse because Zayd
(radhiyallahu anhu) has himself said, 'While writing the copy of the Qur'aan, I could not find the
particular verse of Soorah Ahzaab which I used to hear the Prophet
(sallallahu alayhi wasallam) recite.’ This shows very clearly that the verse under reference was something Zayd (radhiyallahu anhu)
and other Companions remembered very well. On the other hand, it also does not mean that
this verse never existed in writing anywhere, because this verse was obviously there in
the pages of the Qur'aan written during the time of Aboo Bakr (radhiyallahu anhu). Besides that, obviously
enough, this verse was also included in the copies of the Noble Qur'aan which were written
and preserved by the Companions on their own. But, like it was in the days of Aboo Bakr (radhiyallahu anhu),
this time too, all those scattered documents, available with the Companions in writing,
were collected together, therefore Zayd (radhiyallahu
anhu) and others with him did not write down any verse into these
copies of the Qur'aan until such time when they did find it in those written documentation as well.
As much, the fact was that other verses were found written separately too with several
Companions, but this verse from Soorah Ahzaab was not found written separately with anyone
else except Khuzaymah
(radhiyallahu anhu). (radhiyallahu anhu)
had all copies kept by different Companions burnt so that all copies of the Qur'aan became
uniform in terms of the script, incorporation of accepted readings and the order of
chapters, leaving no room for any difference between them.