Historical transformation on why and how to recognize the first lost hadith sources

 From the perspective of the predecessors, one of the most basic criteria for the validation of hadith was the criteria of source knowledge and simply referring to the books of Rajali, which caused the abandonment of many hadith sources. Looking for historical change, we are looking for new methods and clues to identify authentic hadith sources. The most important benefits of recognizing the first sources of hadiths can be the identification of books trusted by the old narrators, the general review of narrations and the book of a narrator, the identification of different versions and the resolution of conflicting narrations. Paying attention to the document of transmission of the first sources in religious sources, repeating the chain of documents leading to the author of the book in hadith sources, and matching the topic of narrations with the title of the author's book are among the methods of identifying the collection of hadith from written sources. Etymological analyses, minimizing speculations, avoiding conjectures and weak probabilities, and explaining how to identify lost hadith sources with the help of providing seven clues to prove the existence of a book as a written source, are among the most important findings and achievements of this research.