Hadith report, the scale of the report's transmission, the routes through which the report was transmitted, and the individual narrators involved in its transmission. On the basis of these criteria, various classifications were devised for hadith. The earliest comprehensive work in hadith studies was Abu Muhammad al-Ramahurmuzi's "al-Muhaddith al-Fasil", while another significant work was al-Hakim al-Naysaburi's "Ma‘rifat ‘ulum al-hadith". Ibn al-Salah's "ʻUlum al-hadith" is considered the standard classical reference on hadith studies. By means of hadith terminology, hadith are categorized as "ṣaḥīḥ" (sound, authentic), "ḍaʿīf" (weak), or "mawḍūʿ" (fabricated). Other classifications used also include: "ḥasan" (good), which refers to an otherwise
Hadith terminology "musnad" ( meaning "supported") "hadith" as: A "musnad hadith" should not be confused with the type of "hadith" collection similarly termed "musannaf", which is arranged according to the name of the companion narrating each "hadith". For example, a "musnad" might begin by listing a number of the "hadith", complete with their respective "sanads", of Abu Bakr, and then listing a number of "hadith" from Umar, and then Uthman ibn Affan and so on. Individual compilers of this type of collection may vary in their method of arranging those Companions whose "hadith" they were collecting. An example of this type of