Sahihi Müslim. Muslim lived a couple of centuries after the Prophets death and worked extremely hard to collect his ahadith. His collection is considered to be one of the most authentic collections of the Sunnah of the Prophet and along with Ṣaḥīḥ al-Bukhārī forms the Sahihain or the Two Sahihs It contains roughly 7500.
Sahih Muslim 4.
Generally the scholars of Maghrib Morocco gave preference to Sahih Muslim over Sahih Bukhari as Abu Ali Neshapuri said. Sahih Muslim -complete in 7 volumes as 7 volume set- is the most authentic book of Hadith after Sahih Al-Bukhari and contains 7563 Ahadith. When one of you yawns he should keep his mouth shut with the help of his hand for it is the devil that enters therein. The constituents of one of you are collected for forty days in his mothers womb in the form of blood after which it becomes a clot of blood.