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 "the documentation" of the Sunnah. Another source (Joseph A. Islam) distinguishes between the two saying: Whereas the 'Hadith' is an oral communication that is allegedly derived from the Prophet or his teachings, the 'Sunna' (quite literally: mode of life, behaviour or example) signifies the prevailing customs of a particular community or people. ... A 'Sunna' is a practice which has been passed on by a community from generation to generation en masse, whereas the Ahadith are reports collected by later compilers often centuries removed from the source. ... A practice which is contained within the Hadith may well be regarded