” 22.  Zaid bin Thabit’s Second Account of the Collection of the Qur’an, in Hadith 509, proves that the Koran was never compiled into one volume during the life time of Muhammad.

The Hadith shows how it was feared that portions of the Qur’an would be lost. This indicates that there was not yet a complete recognized cannon. Abu Bakr was not familiar with a collected Qur’an and said that Muhammad had never decreed it be collected. The best that was available was “fragmentary scripts.”

When ordered to compile the Qur’an, Zaid at first refused on the grounds that Muhammad had not done so. Zaid declared that it would be a difficult task. There were three methods of recording Zaid searched out – palm leaf stalks, thin white stones and also from the men who knew it by heart. One verse was found only in the possession of one man.”

Quoted from:  http://www.bible.ca/islam/islam-encyclopedia-westerners-need-to-know-list.htm