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
Criticism of Hadith According to Racha El Omari, early Mutazilites believed that hadith were susceptible to "abuse as a polemical ideological tool"; that the "matn" (content) of the hadith -- not just the "isnad" -- ought to be scrutinized for doctrine and clarity; that hadith "supported by some form of "tawātur"", i.e. by a large number of "isnād" strands, each beginning with a different Companion, were valid. In writing about "mutawatir" (transmitted via numerous chains of narrators) and "ahad" (any ahadith that is not "mutawatir") and its importance from the legal theoretician's point of view, Wael Hallaq notes the medieval scholar Al-Nawawi argued