Hadith of the Ark ""perished whoever turned away from it"" also comes along." And in his another book, Al-Heithami indicates this hadith as authentic (sahih). According to Dahlan, the authenticity of this hadith is confirmed by different sources. The hadith implies the absolute priority of "Ahl al-Bayt" to all others, otherwise Muhammad would have forbidden to follow them. According to Shia scholars, the only path to salvation is by following the "Ahl al-Bayt", so they must be infallible ("Ma'sum"), otherwise they will mislead their followers. If they are infallible, they must be Imam definitely. According to this hadith, they are the criterion of distinguishing
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