Some Features of al-Kutub al-Sitta

• Most of the hadiths contained in these six books are considered sahih (authentic and reliable) by scholars. Although all of the authors said they aimed to include mostly authentic hadiths, none of them claimed that they were able to gather all of the authentic hadiths. Therefore, it is a fact that there are many authentic hadiths not contained in al-Kutub al-Sitta as well.
• The first scholar who undertook a project of composing a book to contain only authentic hadiths was Imam al-Bukhari; others followed the path that he had led.
• It has been reported in the sources that when these books are evaluated in terms of the authenticity of hadiths contained in them and of their sources, the books by al-Bukhari and Imam Muslim are at the highest level, followed by the works of Abu Davud, Tirmidhi and Nasaai's books. However, the superiority or primacy of al-Bukhari and Muslim's works should only be perceived as a general attribute; that is to say, if each hadith is analyzed separately, different levels of authenticity can be attributed to them, regardless of the book which contains them. In other words, the superiority of al-Bukhari's Sahih, or the fact that Ibn Majah's Sunan is the last one on the list, does not indicate the degree of the strength or weakness of any individual hadith.
• In all the books of the al-Kutub al-Sitta, the hadiths are classified according to their subject matters; all the hadiths regarding a topic are gathered under similar titles. However, there are some differences among the authors in terms of their classification of different topics and their titles, for each of them employ their own unique methods of classification.
• In al-Kutub al-Sitta, an individual authentic hadith can be found sometimes in all of the six books, at other times in only one of them; but mostly the hadith will be included in several of the books. An individual hadith may or may not be repeated several times by the books.
• All six authors lived in the 3^rd century (after the Hijrah). Except for al-Nasaai (d. 303/ 915), four of the authors were students of al-Bukhari at one point in their careers. That is to say, almost all of them were contemporaneous and had a relationship of teacher-student with al-Bukhari.
• Virtually all of the authors wrote separate books on the biographies of the narrators from whom they themselves narrated the hadiths. For, before anything else, they investigated and criticized their own fellow narrators in the chains of narration.
• The authors of al-Kutub al-Sitta did not receive, nor did they expect, any material support or award from the generous caliphs and administrators who were willing to support them in their lifetime.
• When taken together, the books comprising the al-Kutub al-Sitta and their differing features represent the entire hadith literature in terms of their content and methodology. Thus, they complement each other in different ways: if one wishes to find more information regarding the Islamic fiqh, they can resort to al-Bukhari's Sahih; one wishing fewer ta'liqat in hadith can go to Muslim's Sahih; one who wishes for more information on the narration of hadiths can look it up in Tirmidhi's Jami'; one who wishes to find hadiths only on fiqh topics should consult Abu Davud's Sunan; one who wishes to see a perfect classification according to the topics in fiqh could resort to Ibn Majah's Sunan. Finally, many of these features are simultaneously included in the Sunan of al-Nasaai.
• None of the authors of al-Kutub al-Sitta were followers of a school of thought in Islamic fiqh; yet they themselves were deeply knowledgeable in fiqh.