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
Introduction to the Science of Hadith chapters, each covering a hadith related issue. The first 33 chapters describe the various technical terms of hadith terminology which describe the conditions of a hadith's authenticity, or acceptability as a basis for Islamic jurisprudence. The following chapters relate to the "isnād", or chain of narration. Next are a series of chapters pertaining to the etiquette to be observed by hadith scholars and manners of transcription. The last chapters describe various issues relating to the narrators of hadith including naming conventions. Ibn al-Ṣalāḥ began the "Introduction" as a series of lectures he dictated to his students in Damascus ending in