Hadith of the Twelve Successors will be anything other than twelve. The twelve successors from the hadith (traditions of the prophet Muhammad) are already known as The Twelve Imams. Two hadiths form the basis and understanding of the 12 successors of the Prophet Muhammad: the hadith of the two weighty things and the hadiths regarding the 12 khalifs. One of the most authentic hadith (traditions of the sayings of the Prophet Muhammad) is Hadith thaqalain in which the Prophet Muhammad tells the muslims that he is leaving behind two weighty things, The quran and his ahlul bayt. Al-Tirmidhi in his Sunan records the following tradition:
Introduction to the Science of Hadith authored an abridgement: The following have set "Introduction" to verse, adding some content in the process: The numerous editions of the "Introduction" in its original Arabic include two of the more reliable: The "Introduction" has been translated into English and published as "An Introduction to the Science of Hadith", by Eerik Dickinson, as part of the Great Books of Islamic Civilization series. The translator has provided a biography of Ibn al-Ṣalāḥ derived from numerous sources, in addition to copious footnotes throughout. It is published by Garnet Publishing Limited, Reading, 2006, 356 pgs. Introduction to the Science of Hadith (Ibn al-Ṣalāḥ's)