Muslim ibn al-Hajjaj

Muslim's organising principle in Sahih Muslim is the detail scholars most often cite when explaining why the book stands beside al-Bukhari's rather than simply after it. Where a hadith reaches a compiler through several independent chains of transmission, each with its own sequence of narrators, al-Bukhari frequently distributes those versions across different chapters according to the legal point each version best illustrates. Muslim instead gathers every chain for a given report into one place, one after another, so a reader can compare the wording and the narrators of every transmitted version at once rather than hunting through the book for scattered variants.

This is a different kind of usefulness from al-Bukhari's, oriented toward the technical study of transmission itself rather than toward direct legal application, and later scholars of hadith methodology have often preferred Sahih Muslim as a training text for exactly that reason. Muslim also wrote a substantial introduction setting out his methodology explicitly, an unusually direct statement of principle for the genre, in which he distinguishes the narrators he judged reliable enough to include from those he judged short of that standard and explains why a report supported only by the latter has no place in his book.

The pairing of the two Sahihs as a single unit, "the two Shaykhs" in the traditional phrase, reflects how completely later Sunni scholarship came to treat their combined standard as the benchmark against which every other hadith collection, including the four Sunan works, would be measured.

Muslim's training took him through the same network of ninth-century scholarship that produced al-Bukhari, and the overlap between their teachers is part of why their two books, despite real differences in arrangement, agree on the great majority of the material each includes. He travelled to Iraq, the Hejaz, Syria and Egypt over the course of his education, a pattern typical of the hadith scholarship of his generation, in which authority was built by collecting direct oral transmission from as many recognised carriers of the tradition as a scholar could reach rather than by working from written compilations alone.

The most widely repeated story about his death, that he wore himself out testing a hadith against a basket of dates one at a time until the basket was empty, belongs to the same genre of anecdote that surrounds al-Bukhari's reported feats of memory: whether or not the detail is literally accurate, it is preserved because it illustrates, in a memorable form, the intensity of textual scrutiny his generation of scholars was understood to have practised as a matter of course.

His book's influence outlasted the immediate circle of his students. Commentaries on Sahih Muslim became a standard genre of their own within a few generations, and the introduction in which he laid out his method for judging narrators is still read as one of the clearest early statements of the discipline hadith criticism became.