over a century, are significant. The inner face of the octagon include the declaration of faith and verses describing the powers of God. Next Muhammad is introduced, with a blessing that, though uncited in the Quran, was already in use in 694. Then Christians are preached about the prophet-hood and mortality of Jesus, followed by the claim that God is sufficient unto Himself. At the end, people are commanded to bend to His will and punishment is threatened otherwise. The absence of contemporaneous corroborating material from the very first century of Islam has raised numerous questions as to the authenticity of the account provided by later traditionalist sources. All that is preserved from this time period are a few commemorative building inscriptions and assorted coins. However, some scholars deny such a belittlement of key sources from the era. Besides the Dome of the Rock inscriptions mentioned above, there are also brief Quranic passages on coins issued from the time of Abd al-Malik ibn Marwan (697-750). These passages include the shahadah, verses 112:1-3 or -4 complete except for the initial basmallah and the introductory word "say", and part of 9:33, but with some variations: "He sent him with the guidance and the Religion of Truth, that He may cause it to prevail over all religion..." Similar to the contemporary inscriptions at the Dome of the Rock these portions are clearly intended to declare the primacy of the new religion of Islam over Christianity, in particular. Skeptical scholars, nonetheless, point out that the earliest account of Muhammad's life by Ibn Ishaq was written about a century after Muhammad died and all later narratives by Islamic biographers contain far more details and embellishments about events which are entirely lacking in Ibn Ishaq's text. Patricia Crone, studying the origins of the Quran, has focused on the examination of the vast body of the Greek, Armenian, Hebrew, Aramaic, Syriac, and Coptic accounts of non-Muslim neighbours of the 7th and 8th centuries which in many cases contradict the traditional Islamic narratives. She argues that the consistency of the non-Muslim sources spread over a large geographic area would tend to rule out a non-Muslim anti-Islamic motive to these sources. The sceptic approach has been further expanded by Christoph Luxenberg, who supports claims for a late composition of the Quran, and traces much of it to sources other than Muhammad. Luxenberg is known for his thesis that the