then Abu ʿAbd al-Rahman Ahmad ibn Shuʿayb al-Nasaʾi, d. 303 AH; Abu ʿIsa Muhammad ibn ʿIsa al-Tirmidhi, d. 279 AH; and Abu ʿAbd Allah Muhammad ibn Yazid Ibn Majah al-Qazwini, d. 273 AH.

These works are the ones collectively renowned as “the Six Books,” and they have enjoyed special, extensive attention from the scholars, both in regard to their contents and to the reliability of their transmitters.

The first of these six is the Sahih of Imam Abu ʿAbd Allah al-Bukhari, which stands as the most authentic hadith compilation ever produced. Next in rank comes the Sahih of Imam Muslim. Both books have been the object of exceptional scholarly care because their authors strove to gather a large proportion of what is authentically traced back to the Messenger of Allah ﷺ. Yet the two imams never intended—or claimed—to encompass every sound report, and many authentic hadiths remain outside their collections. Still, the material contained in the two Sahihs as a whole