Criticism of Hadith thus provides "certainty of knowledge" of what Muhammad said, in fact it is only the much rarer subset of sahih -- "mutawatir" hadith -- that provide certain knowledge. "Mutawatir" means the report "of a large number of narrators whose agreement upon a lie is inconceivable. This condition must be met in the entire chain from the origin of the report to the very end." However, according to Wael Hallaq, "the bulk of hadith with which the traditionists dealt, and on the basis of which the Jurists derived the law" were known as "ahad" — i.e. non-"mutawatir" hadith; Hadith without "textually
Hadith terminology terminology, it refers to a "hadith" not fulfilling all of the conditions necessary to be deemed "mutawatir". "Hadith ahad" consists of three sub-classifications also relating to the number of narrators in the chain or chains of narration: An "ʻaziz" () "hadith" is any "hadith" conveyed by two narrators at every point in its "isnād" (chain of narrators). A "gharib" () "hadith" is one conveyed by only one narrator. Al-Tirmidhi's understanding of a "gharib hadith", concurs to a certain extent with that of the other traditionists. According to him a "hadith" may be classified as "gharib" for one of the following