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 highly of Mutawatir: However, orthodox hadith scholars find non-mutawatir hadith adequate. "According to the majority of the ulama of the four Sunni schools, acting upon ahad is obligatory even if ahad fails to engender positive knowledge. Thus, in practical legal matters," but not in "matters of belief", "a preferable "zann" [meaning, speculative] "is sufficient as a basis of obligation." Ibn al-Salah ( (d. 643/1245), "one of the most distinguished traditionists of the muta'akhkhirun", argues (according to Farooq), that because mutawatir type hadith is rare, "for much of Islamic praxis, certainty of knowledge is neither feasible nor required. Rather, probable or