Dr. Marawan Shahin, Professor of Hadith and its Sciences, Faculty of Usul Ad-Din (Theology),Al-Azhar Univ. states:
“1- According to the consensus of Muslim scholars, the arrangement of the verses and surahs of the Qur’an has been done according to revelation (wahi). We read in the authentic sunnah of the Prophet (peace and blessings be upon him) that Jabril used to tell the Prophet (peace and blessings be upon him) to put such and such a verse after a certain verse in a certain surah. The same applies to surahs which have been arranged according to revelation as Jabril (peace and blessings be upon him) used to tell the Prophet (peace and blessings be upon him) to put this surah after such and such a surah.
2- Names of surahs as well as their arrangement was also put by revelation.
3- In the lifetime of the Prophet (peace and blessings be upon him), his companions and the scribes of revelation used to write down the Qur’an on palm scrolls and bones. You refer to Almighty Allah’s saying, “Which none toucheth save the purified.” (Al-Waqi`ah: 79) It refers to the text of the Glorious Qur’an which is written down on any material and regardless of whether it is written and collected in one mushaf or some suras in papers or any other material. It makes no difference. So, the ruling is binding when the verse you are referring to was revealed as it refers to the text of the Glorious Qur’an written on any material.