Sahih Muslim is a collection of hadith compiled by Imam Muslim ibn al-Hajjaj al-Naysaburi (rahimahullah). His collection is considered to be one of the most authentic collections of the Sunnah of the Prophet (ﷺ), and along with Sahih al-Bukhari forms the "Sahihain," or the "Two Sahihs." It contains roughly 7500 hadith (with repetitions) in 57 books.