Hadith of the Quran and Sunnah authenticity. The Shi'a claim that this hadith is the most authentic of hadiths, claiming that it has been narrated by over 35 companions of Muhammad. The "Hadith al-Thaqalayn" is used by the Shi'a, among other reasons, to support their belief of Ali's succession to Muhammad. Shi'as view this hadith as a clear indication that Muhammad wished to keep the matter of leadership within his own family, starting with his cousin Ali. They believe that Muhammad was clearly indicating that only the "Ahl al-Bayt" have a right to authority and leadership. It is based on this claim that the Shi'as reject
Introduction to the Science of Hadith category, which comprises 21 types, relates to the names of the narrators. This includes the definition of a "ṣaḥābī" (companion), a "tābi`ī" (follower), the time periods of narrators, names and paidonymics among others. Later scholars included additional types of hadith in their own works, with some almost reaching 100. The "Introduction" became the basis for subsequent books in hadith terminology. A number of subsequent scholars followed Ibn al-Ṣalāḥ in the ordering of his book, including al-Nawawī, Ibn Kathīr, al-ʻIraqi, al-Bulqīnī, Ibn al-Jamā`ah, al-Tabrīzī, al-Ṭībī and al-Zirkashī. In many instances this influence was direct, with numerous scholars authoring books indicating its