turn hints at its origin: One thing common to all these theories is the assumption that the sabab is built around the Qur'ānic verse(s) embedded in it. In his extensive survey of early Muslim traditions regarding Muhammad, Rubin upends this consensus (while preserving Rippin's speculation about the ultimately qassaic/story-teller origins of these reports) by arguing that most asbāb originally started as prophetic biographical material into which Qur'anic verses were only later inserted: Rubin bases that conclusion partly upon the very stereotyped way in which "linking words" are used to introduce Qur'anic verse into a report. Mostly, though, he relies upon the existence of multiple parallel non-Qur'anic forms of the narrative for most asbāb. By assuming that a report's link to scripture would not be removed once established, the non-Qur'anic (and thus non-exegetic) version of the report is in fact the original one. Rippin takes issue with this last assumption, though, by arguing that the evidence does not preclude the creation of parallel sīra narratives even after the circulation of a supposedly "authoritative" Qur'anic one. Outline and function The Quran was revealed over a period of nearly twenty three years. Muslim scholars agree that the revelations of the Quran can be divided into two broad types: One type includes passages of the Quran which were revealed in response to specific events, incidents or questions put forward to Muhammad. The second type includes passages of the Quran which were not direct responses to any historical or social development in the life of the Muslim community. A thorough understanding of the first type of passages, therefore, depend on knowing the circumstances of the events which occasioned them. Such knowledge is an important tool for explaining the meanings of this type of Quranic verses. One function of the sabab report is theological. As Rippin notes: The occasion of revelation's primary function, though, is exegetical, and by enumerating its various uses within Qur'anic interpretation we visit nearly all the problems of concern for classical Muslim exegetes. These problems span the hermeneutical spectrum, from the most basic units of linguistic meaning to such technical intellectual disciplines as law and philosophy and all points in between. A major underlying difficulty encountered at all levels is the Qur'an's lack of structure. This extends beyond the question of temporal ordering to one of basic unity of thought and expression: The various levels of interpretation along with their typical problems