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 "with something, such as numerous chains of narration, strengthening it." Ibn Hajar's definitions indicate that there are five conditions to be met for a particular "hadith" to be considered "ṣaḥīḥ": A number of books were authored in which the author stipulated the inclusion of "ṣaḥīḥ hadith" alone. According to Ahl al-Sunna, this was only achieved by the first two books in the following list: "Ḥasan" ( meaning "good") is used to describe "hadith" whose authenticity is not as well-established as that of "ṣaḥīḥ hadith", but sufficient for use as supporting evidence. Ibn Hajar defines a "hadith" that is "ḥasan lithatihi"""ḥasan"