This scholar created categories like hasan, mutawatir, mawdu', ahad, and (*) da'if within which he meticulously placed the isnad, or chain of narrators, which is why he is considered the most reputable source on the sayings of Muhammad.
Anecdotally, when this scholar was criticized for not taking notes while studying in Basrah, he relayed 15,000 stories from memory, demonstrating that he didn't need to. This scholar's major work is organized into 97 chapters, each meant to illustrate a particular topic of fiqh. A long with Muslim al- Hajjaj, this scholar is one of the two most famous teachers of al-Tirmidhi - all three men are best known for their work on the same religious matter. This scholar created categories like hasan, mutawatir, mawdu', ahad, and (*) da'if within which he meticulously placed the isnad, or chain of narrators, which is why he is considered the most reputable source on the sayings of Muhammad. For 10 points, name this 9th-century Persian scholar, the author of the most authoritative, or sahih, of all compilations of hadith.
Anecdotally, when this scholar was criticized for not taking notes while studying in Basrah, he relayed 15,000 stories from memory, demonstrating that he didn't need to.
Muhammad ibn Ismail al-Bukhari [or Imam Bukhari; accept Sahih al-Bukhari; do not accept or prompt on "Muhammad"]