An summarised text detailing the rules governing the Criticism of Hadeeth.
From its introduction -’A hadith (pl. ahadith) is composed of two parts: the matn (text) and the isnad (chain of reporters). A text may seem to be logical and reasonable but it needs an authentic isnad with reliable reporters to be acceptable; ‘Abdullah b. al-Mubarak (d. 181 AH) is reported to have said, “The isnad is part of the religion: had it not been for the isnad, whoever wished to would have said whatever he liked.”
During the lifetime of the Prophet (SAS) and after his death, his Companions (Sahabah) used to refer to him when quoting his sayings. The Successors (Tabi’un) followed suit; some of them used to quote the Prophet (SAS) through the Companions while others would omit the intermediate authority – such a hadith was known as mursal (loose). It was found that the missing link between the Successor and the Prophet (SAS) might be one person, i.e. a Companion, or two persons, the extra person being an older Successor who heard the hadith from the Companion.’