 The Usuli scholars stress the importance of scientific examination of hadiths using ijtihad while the Akhbari scholars take all hadiths from the four Shia books as authentic
.The two major aspects of a hadith are the text of the report (the "matn"), which contains the actual narrative, and the chain of narrators (the "isnad"), which documents the route by which the report has been transmitted.The isnad was an effort to document that a hadith had actually come from Muhammad, and Muslim scholars from the eighth century until today have never ceased repeating the mantra "The isnad is part of the religion — if not for the isnad, whoever wanted could say whatever they wanted."