Hadith root of why there is no single "fiqh" system, but rather a collection of parallel systems within Islam. Much of early Islamic history available today is also based on the hadith, although it has been challenged for its lack of basis in primary source material and the internal contradictions of the secondary material available. Hadith may be "hadith qudsi" (sacred hadith) — which some Muslims regard as the words of God (Arabic: Allah) — or "hadith sharif" (noble hadith), which are Muhammad's own utterances. According to as-Sayyid ash-Sharif al-Jurjani, the hadith qudsi differ from the Quran in that the former
Introduction to the Science of Hadith chapters, each covering a hadith related issue. The first 33 chapters describe the various technical terms of hadith terminology which describe the conditions of a hadith's authenticity, or acceptability as a basis for Islamic jurisprudence. The following chapters relate to the "isnād", or chain of narration. Next are a series of chapters pertaining to the etiquette to be observed by hadith scholars and manners of transcription. The last chapters describe various issues relating to the narrators of hadith including naming conventions. Ibn al-Ṣalāḥ began the "Introduction" as a series of lectures he dictated to his students in Damascus ending in