James E. (University of Cambridge, UK) Montgomery & Gregor (University of Basel, Switzerland) Schoeler 
The Oral and the Written in Early Islam [PDF ebook] 

Made up of a number of seminal articles that are translated for the first time in English, this prestigious book from Gregor Schoeler gives a reasoned, informed and comprehensive overflow of how the written and the spoken interacted, diverged and received cultural articulation among the Muslim societies of the first two centuries of the Hijra.