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 al-Ṣalāḥ, in his "Introduction", codified the terminology established by those scholars before him based upon his reading of their works. He did so by citing some of those scholarly statements in the earlier works and deducing from them common terms and definitions in the manner of a scholar authoring a book of "fiqh" (jurisprudence). In this manner, his book was based upon those principles established by the earlier hadith specialists combined with some elements of "fiqh". An example of this would be the inclusion of the division of hadith into "mutawātir" and "āḥād". He therefore only mentioned the statements of