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
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