Hadith of the two weighty things went to Zayd b.Arqam, one of the transmitters of the standard Ghadir Khumm. Zayd said to them that he has "forgotten some [of what he had heard from the prophet]" but he began to recite Hadith al-Thaqalayn for them as words that heard from prophet in The event of Ghadir Khumm. As the Allameh Tabataba'i said, some points can be driven from this hadith such as "the Holy Quran will remain until the day of Judgment, the progeny of the Mohammad prophet will remain". There will be any period of time that Shia Imam doesn't exist to guide Muslims. All
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)