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
Introduction to the Science of Hadith al-Kattānī. `Āʼishah bint `Abd al-Raḥmān said in the foreword of her edition of the "Introduction": His book about the sciences of hadith is the best known of his works without comparison, to the extent that it is sufficient to say, "the Book of Ibn al-Ṣalāḥ", the intent being understood due to its popularity and stature. With the previous scholars, its subject matter overcame it, thus being referred to as, "the Book of Ibn al-Ṣalāḥ about `Ulūm al-Ḥadīth" or as he referred to it in its opening pages, "the Book of Familiarity with the Types of `Ulūm al-Ḥadīth". It has become