The Kutub al-Sittah

These are the six universally accepted books of ḥadīth¹: Ṣaḥīḥ al-Bukhārī, Ṣaḥīḥ Muslim, Sunan al-Nasāʾī, Sunan Abī Dāwūd, Jāmiʿ al-Tirmidhī, and Sunan Ibn Mājah.

Two factors broadly stand behind the authenticity of a ḥadīth:

• Ḍabṭ: the narrator's competence in understanding and accuracy of transmission.
• Mulāzamah: the time he spent with his teacher.

These give five working categories of aḥādīth:

1. Kathīr ḍabṭ, kathīr mulāzamah: narrators are very competent and have spent a long time with their teacher
2. Kathīr ḍabṭ, qalīl mulāzamah: narrators are very competent but have spent little time with their teacher
3. Qalīl ḍabṭ, kathīr mulāzamah: narrators are not so competent but have spent a long time with their teacher
4. Qalīl ḍabṭ, qalīl mulāzamah: narrators are not so competent and have spent little time with their teacher
5. Ḍuʿafāʾ and majāhīl: those who are weak and unknown

The authors of the six books each set conditions for inclusion in their collections. In terms of which categories they accept:

1. al-Bukhārī: takes from (1) and some of (2) (numbers refer to the list above)
2. Muslim: takes both (1) and (2)
3. al-Nasāʾī: takes from (1), (2), and (3)
4. Abū Dāwūd: takes from (1), (2), and (3), and uses (4) as supporting evidence, but mentions if it is reliable or not
5. al-Tirmidhī: takes from (1), (2), (3), (4), and occasionally (5)
6. Ibn Mājah: takes from (1), (2), (3), (4), and (5)

Footnotes

1. There is ikhtilāf as to the inclusion of Ibn Mājah in the list. ↩