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
Hadith terminology in and of itself"with the same definition a "ṣaḥīḥ hadith" except that the competence of one of its narrators is less than complete; while a "hadith" that is "ḥasan ligharihi" ("ḥasan due to external factors") is determined to be "ḥasan" due to corroborating factors such as numerous chains of narration. He states that it is then comparable to a "ṣaḥīḥ hadith" in its religious authority. A "ḥasan hadith" may rise to the level of being "ṣaḥīḥ" if it is supported by numerous "isnād" (chains of narration); in this case that "hadith" would be "ḥasan lithatihi" (""ḥasan" in and of itself")