Arab literature was for a long time entrusted to the recollection of its readers. For instance, after the death in 815 of the great poet Abu Nuwas, no copy of his work was found; the poet had learned by heart all his poems, and in order to set them down on paper the scribes had to resort to the memory of those who had listened to the master. Precision of recall was deemed all-important, and throughout the Islamic Middle Ages, it was considered more valuable to learn by listening to books read out loud than by private study, because the text then entered the body through the mind and not merely through the eyes. Authors published not so much by transcribing their work themselves as by dictating it to their assistants, and students learned by hearing those texts read out to them or by reading them to a teacher. Because of the Islamic belief that only oral transmission was truly legitimate, memory (not its physical representation in the solid world of books and manuscripts, though these were important enough to be treasured in schools and mosques) was deemed to be the great repository of a library.”‘ Up to a point, “library” and “memory” were
synonymous.
The Library at Night by Alberto Manguel
Bewildered Creatures 