The Qur'an was sometimes revealed to respond to various events and incidents. Sometimes it was revealed to support the Prophet (saws) who was faced with many questions, whether by Muslims or non-Muslims, and hardships. Other times was revealed for legislation and for putting rules to govern the social, economical, and political life of Muslims.
The first verses to be revealed, according to the most correct opinion of scholars, are the first five verses of Surat Al-`Alaq, which happens to be Chapter 96 of the 114 chapters of the Qur'an.
Order of Verses
Muslim scholars agree that the order of the verses in every chapter was done or commanded by the Prophet (saws) himself following the commands of Almighty Allah.
The Prophet (saws) once told his Companions after he had received a certain revelation that the arch-angel Gabriel had specified for him the particular order of verses (Ahmad).
There are also many incidents narrated in the books of Sunnah regarding the Prophet's (saws) recitation during prayer. The Companions used to pray every day behind the Prophet (saws) and he used to recite the Qur'an in the order given to him by Allah, and they used to learn and memorize from his recitation.
There have never been any incident in which any of the Companions reciting in any order that violated the order of the verses showed to us by the Prophet (saws).
Order of Surahs
As for the order of the surahs (chapters), the most accepted view is that it was also applied following an instruction given by Almighty Allah. It has been recorded that the Prophet (saws) reviewed the Qur'an with the arch-angel Gabriel 24 times all within his life.
Every year, he used to review it once during the month of Ramadan with Gabriel. During the final year of the Prophet's life, Gabriel revised the Qur'an twice with the Prophet (saws) as a way of confirming it. The Prophet (saws), in turn, used to follow this order in teaching his Companions and communicating the message to them.
Significance of Order
The question of why a surah like Surat Al-`Alaq, which was revealed first not put first in the mushaf (a physical copy of the Qur'an), this will require us to search more in the Qur'an and explore some of its secrets. A deeper look into the whole matter will show us that the order of the Qur'an has a purpose and the revelation of the Qur'an also has a purpose.
For instance, the revelation of the Qur'an responding to specific problems or incidents carries the purpose of solving these problems or providing guidance in these incidents.
During the first 13 years of Islam, the main task of the Prophet (saws) was to call people to Islam based on the Qur'anic revelations that focused on the Oneness of Allah and righteous conduct.
When Muslims migrated to Madinah and an Islamic community started to be well-established and new challenges emerged, the main focus of the revelation was to regulate the life of Muslims through detailing the rulings pertaining to different acts of worship and setting punishments for crimes and so on.
This shows us that the revelation in each of the two stages has a purpose. When the revelation stage was completed, the whole Qur'an was there and the whole message was put in the order that was intended for it to stay till the Day of Judgment.
Explanation of Order
Such an order serves in delivering the message the Qur'an is put for, as it has got another purpose.
If you look at the first surah of the Qur'an, namely Al-Fatihah, you can perceive that it acts as a summary for the structure and the message of the Book (Qur'an) ahead of every reader.
Being Umm Al-Qur'an (the Mother of the Qur'an), it carries all its themes; it summarizes them. It tells us who Allah is: the source of all love and mercy. Therefore, knowing who He is, we should be thankful to Him and worship Him alone. We should seek His help, and He has all the power to give us whatever we need. It makes it clear that Allah is the only One Who can really guide. It speaks about life after death and the consequences of human action and behavior.
The same holds true for Surat Al-Baqarah. The first verses speak about the fact that this Book is above all doubts and it is beyond the abilities of doubters to try to challenge its validity. Then it gives a hint on its main theme — guiding the righteous — and then goes on to speak about the beginning of creation and the story of Adam to establish the theme that humankind is here on earth as a vicegerent of the Creator and should use the Book as a manual to carry out the mission in the right way.
All these themes and messages cannot be carried except through this logical order in which Allah commanded for the Qur'an to be put. If a surah like Al-`Alaq was to be put at the beginning instead of Al-Fatihah, it could have given a significance of course and give a message, but not the exact fully wonderful message that we can get from the order of the Qur'an as it is now.
Why Al-`Alaq in the Current Order?
As for why Surat Al-`Alaq is mentioned in this specific order in the Qur'an, scholars hold the view that in the previous surah of At-Tin, Allah says what means that He has created humans in the best make (At-Tin 95:4). The details of that creation are cited in Surat Al-`Alaq:
*{Read in the name of your Lord Who created. Created humans, out of a (mere) clot of congealed blood.}* (Al-`Alaq 96:1-2)