From the (in)famous, Wikipedia:
Luxenberg, like many scholars before him, remarks that the Qur'an contains much ambiguous and even inexplicable language. He asserts that even Muslim scholars find some passages difficult to parse and have written reams of Quranic commentary attempting to explain these passages. However, the assumption behind their endeavours has always been that any difficult passage is true, meaningful, and pure Arabic, and that it can be deciphered with the tools of traditional Muslim scholarship. Luxenberg accuses Western academic scholars of the Qur'an of taking a timid and imitative approach, relying too heavily on the biased work of Muslim scholars.
The book's thesis is that the Qur'an was not originally written exclusively in Arabic but in a mixture with Syriac, the dominant spoken and written language in the Arabian peninsula through the 8th century.
“What is meant by Syro-Aramaic (actually Syriac) is the branch of Aramaic in the Near East originally spoken in Edessa and the surrounding area in Northwest Mesopotamia and predominant as a written language from Christianization to the origin of the Koran. For more than a millennium Aramaic was the lingua franca in the entire Middle Eastern region before being gradually displaced by Arabic beginning in the 7th century.”
Luxenberg argues that scholars must start afresh, ignore the old Islamic commentaries, and use only the latest in linguistic and historical methods. Hence, if a particular Quranic word or phrase seems meaningless in Arabic, or can be given meaning only by tortured conjectures, it makes sense -- he argues -- to look to the Aramaic and Syriac languages as well as Arabic.
Luxenberg also argues that the Qur'an is based on earlier texts, namely lectionaries used in the Christian churches of Syria, and that it was the work of several generations who adapted these texts into the Qur'an we know today.
