Proof of The Preservation of the Quran

There are hundreds of religions flourishing around the world: Christianity, Islam, Buddhism, Sikhism, Hinduism, Judaism, Bahaism, Babism, Zoroastrianism, Mormonism, Jehovas Witnesses, Jainism, Confucianism etc. And each of these religions claim that their scripture is preserved from the day it was revealed (written) until our time. A religious belief is as authentic as the authenticity of the scripture it follows. And for any scripture to be labeled as authentically preserved it should follow some concrete and rational criteria.

Imagine this scenario: A professor gives a three hour lecture to his students. Imagine still that none of the students memorized this speech of the professor or wrote it down. Now forty years after that speech, if these same students decided to replicate professor's complete speech word for word, would they be able to do it? Obviously not. Because the only two modes of preservation historically is through writing and memory. Therefore, for any claimants to proclaim that their scripture is preserved in purity, they have to provide concrete evidence that the Scripture was written in its entirety AND memorized in its entirety from the time it was revealed to our time, in a continuous and unbroken chain. If the memorization part doesn't exist parallel to the written part to act as a check and balance for it, then there is a genuine possibility that the written scripture may loose its purity through unintentional and intentional interpolations due to scribal errors, corruption by the enemies, pages getting decomposed etc, and these errors would be concurrently incorporated into subsequent texts, ultimately loosing its purity through ages.

Now, of all the religions mentioned above, does any one of them possess their scriptures in its entirety BOTH in writing AND in memory from the day of its revelation until our time. None of them fit this required criteria, except one: This unique scripture is the Qur'an - revelation bestowed to Prophet Muhammad (peace be upon him) 1,418 years ago, as a guidance for all of humankind.
Transmission of the Qur'an: Oral & Written

Lets analyze the claim of the preservation of the Quran…
1. Memorization

'In the ancient times, when writing was scarcely used, memory and oral transmission was exercised and strengthened to a degree now almost unknown' relates Michael Zwettler.[1]
Prophet Muhammad (S): The First Memorizer

It was in this 'oral' society that Prophet Muhammad (S) was born in Mecca in the year 570 C.E. At the age of 40, he started receiving divine Revelations from the One God, Allah, through Archangel Gabriel. This process of divine revelations continued for about 22.5 years just before he passed away.

Prophet Muhammad (S) miraculously memorized each revelation and used to proclaim it to his Companions. Angel Gabriel used to refresh the Quranic memory of the Prophet each year.

'The Prophet (S) was the most generous person, and he used to become more so (generous) particularly in the month of Ramadan because Gabriel used to meet him every night of the month of Ramadan till it elapsed. Allah's Messenger (S) use to recite the Qur'an for him. When Gabriel met him, he use to become more generous than the fast wind in doing good'. [2]

'Gabriel used to repeat the recitation of the Qur'an with the Prophet (S) once a year, but he repeated it twice with him in the year he (Prophet) died'. [3]

The Prophet himself use to stay up a greater part of the night in prayers and use to recite Quran from memory.
Prophet's Companions: The First Generation Memorizers

Prophet Muhammad (S) encouraged his companions to learn and teach the Quran:

'The most superior among you (Muslims) are those who learn the Qur'an and teach it'. [4]

'Some of the companions who memorized the Quran were: 'Abu Bakr, Umar, Uthman, Ali, Ibn Masud, Abu Huraira, Abdullah bin Abbas, Abdullah bin Amr bin al-As, Aisha, Hafsa, and Umm Salama'. [5]

'Abu Bakr, the first male Muslim to convert to Islam used to recite the Quran publicly in front of his house in Makka'. [6]

The Prophet also listened to the recitation of the Qur'an by the Companions: 'Allah Apostle said to me (Abdullah bin Mas'ud): "Recite (of the Quran) to me". I said: "Shall I recite it to you although it had been revealed to you?!" He Said: "I like to hear (the Quran) from others". So I recited Sura-an-Nisa' till I reached: "How (will it be) then when We bring from each nation a witness and We bring you (O Muhammad) as a witness against these people?"' (4:41) 'Then he said: "Stop!" Behold, his eyes were shedding tears then'. [7]

Many Quranic memorizers (Qurra) were present during the lifetime of the Prophet and afterwards through out the then Muslim world.

'At the battle of Yamama, many memorizers of the Quran were martyred. 'Narrated Zaid bin Thabit al Ansari, who was one of those who use to write the Divine Revelations: Abu Bakr sent me after the (heavy) casualties among the warriors (of the battle) of Yamama (where a great number of Qurra were killed). Umar was present with Abu Bakr who said: "Umar has come to me and said, the people have suffered heavy casualties on the day of (the battle of) Yamama, and I am afraid that there will be some casualties among the Qurra (those who memorized the entire Quran) at other place…"' [8]

'Over the centuries of the Islamic Era, there have arisen throughout the various regions of the Islamic world literally thousands of schools devoted specially to the teaching of the Quran to children for the purpose of memorization. These are called, in Arabic, katatib (singular: Kuttab). It is said that the Caliph 'Umar (634-44) first ordered the construction of these schools in the age of the great expansion'. [9]