Sihah al Sitta or the 'six correct books' is the name given to six collections of Hadith, which are considered standard and most authentic by all Muslims. These are:
1. Sahih of Muhammad bin Ismail al Bukhari (d.236 A.H.) His Sahih is considered to be next to the Quran in authenticity.
2. Sahih of Muslim bin Qushairi (d.261 A.H.). His Sahih is the next most important collection of hadith.
3. Sunan of Ibn Majah (d.275 A.H.).
4. Jame of Abu Isa al Tirmizi (d.279 A.H.)
5. Sunan of Abu Abdur Rahman al Nasai (d.303 A.H.)
6. Sunan of Abu Da'ud (d.275 A.H.)
The most important work of hadith literature is the Sahih of al-Bukhari, who Questioned more than one thousand masters of hadith, even those living in very far- away parts of the Muslim world. Another Sahih was compiled almost simultaneously with it. This was the collection of hadith of Muslim bin Qushairi.
These two collections are the ones, which are used most widely by all Muslims.
Ibn Majah travelled widely to collect traditions from the well-known Traditionists of his time. He compiled several works of Hadith of which the most important is the Sunan. In this work, Ibn Majah collected together 4000 traditions in 32 books divided into 1500 chapters. The number of weak (dhaif) traditions it contains is not very large, just about 30. But it does contain some traditions, which are considered by the authorities on the subject to be forged (maudu').
Abu Isa al Tirmizi was a student of Abu Da'ud and his collection follows and improves upon the techniques of classifying the hadith as proposed by his master. Jame of Tirmizi contains all the traditions - legal, dogmatic and historical - that had been accepted by the Muslim jurists of one school or another, as the basis of Islamic law.
Al Nasai' collected hadith in his work Sunan. He entirely ignored the point of view of his senior contemporary, al-Tirmizi on the question of the application of traditions to various problems that might have been made by different schools of the Muslim juriprudence. His main object was to establish the text of traditions and the differences between their various versions, which he quotes extensively. In many places, he gives headings to the differences between the various narrators.
Abu Da'ud was another important compiler of hadith. Before writing his Sunan he examined five lakhs of traditions, and selected from them only 4800 to be put in his book. The whole task took him 20 years to complete. He kept up the scrupulous exactitude of his predecessors in reproducing the traditions, which he had collected. But he differed from them in the standard of his choice. He included in his Sunan not only the 'genuine' traditions (as al-Bukhari and Muslim had done), but also such traditions as had been pronounced by some traditionists to be weak and doubtful.
