1 - Al Mawatta of Imam Malik
Al Mawatta is presumably written during the period 130 – 140 H. Imam Malik took almost 40 years to complete this book. Before al Mawatta a number of hadith compilations had come onto surface but their soundness could not be as much certified as in al Mawatta. Hafiz Ibn Hubban (d.354 H) says: “ Amongst the jurisprudents of Madina of that time Imam Malik is the only person who researched on the soundness of narrators or the narrations. He refrained to quote from those narrators whose soundness was questionable. He neither relates to defective narrations nor includes the ahadith from unsound narrators.

Al Mawatta is one of the earliest collections of hadith that form the basis of Islamic jurisprudence alongside the Qur'an.[2] Nonetheless, is not merely a collection of hadith; many of the legal precepts it contains are based not on hadith at all. The book covers rituals, rites, customs, traditions, norms and laws of the time of the Islamic prophet Muhammad.

The scholars of ahadith have included al Mawatta amongst the top most authentic books on ahadith. Imam Shafa’I (d. 204 H) who was a student of Imam Malik says: “ after Qura’n, on the surface of the earth, there is no other book on earth more authentic and trustworthy than Imam Malik’s al Mawatta”.
Some scholars are of the opinion that this book perhaps stands next to ‘Sahih’ Al Bukhari.[1]

Initially there were 10,000 ahadith in al Mawatta, but after scrutiny 1720 ahadith are now inscribed in Mawatta, that includes; 600 Musnad Marfu’o ahadith, 222 Mursal ahadith, 613 Mauquf ahadith, 285 Statements of tabi’een , Total 1720.

 
Because of the importance of the Al-Muwatta numerous commentaries are written on it.

2 - Musnad Ahmad ibn Hanbal

Imam Ahmad being very fond of ‘sunnah’ has started collection of ahadith au early age of sixteen. This Musnad contains ahadith selected from those of seven hundred thousand ahadith collected by him. He was so strict about the selection of authentic ahadith that the process of scrutiny remained continued till he breathed his last.

Scholars are not yet sure about the total number of ahadith in the ‘Musnad’. However it is estimated to be between 30,000 to 40,000 ahadith. It is said that ‘Musnad’ is the greatest collection of ahadith. It was published in 6 volumes in 1313 H. It is also said that this Musnad more authentic and reliable as compared to other ‘Musaneed’. Some have said that this book equals Sunnan Abu Dawood and Jama’e Tirmidhi. Some opined that this Musnad lags behind Sunnan Abu Dawood and Jama’e Tirmidhi.

 
A number of commentaries and summaries are written by scholars on this Musna Ahmad ibn Hanbal.

 
3 - Sahih Al-Bukhari

Imam Bukhari had written several books, but his most distinguished work was this compilation of ahadith book titled as ‘ al Jaama’e al Sahih Al Musnad min Hadith Rasool Allah sws wa Sunnahi wa Ayyamihi’. Imam Bukhari was inspired by his most beloved teacher Imam Ishaq ibn Rahwayh (161 – 238 H, was muhaddith, faqih, and the Imam of Khurasan of his time) to compile a book that contains only Sahih ahadith. In this book Imam Bukhari collected only those ahadith that fulfilled all the criterion of soundness and reliability of ‘isnad’ and ‘matan’.

From the collected ahadith, Imam Bukhar had inferred the biography of Rasool Allah sws and the principles of ‘fiqh’ (jurisprudence). This book is divided into 97 chapters, that are further subdivided into 3450 chapters. In all this book contains 7275 ahadith. If the repeated ahadith are omitted then the number falls down to 4000 only.

Uncountable commentaries and ‘Sharuh’ (explanations) have been written for this ‘Sahih al-Bukari’, the most prominent one is that of Hafiz ibn Hajar Assqalani, titled as ‘ Fath al-Bari’.

4 - Sahih Muslim

It is the second most authentic hadith collection after Sahih Al-Bukhari, and is highly acclaimed book. Out of 300,000 hadith which he evaluated, approximately 4,000 were extracted for inclusion into his collection based on stringent acceptance criteria. Each report in his collection was checked and the veracity of the chain of reporters was painstakingly established. Muslim is divided into 43 books,containing a total of 7190 narrations. It is estimated that there are a total of 4000 hadiths (without repetition) in Sahih Muslim.

In this ‘Sahih’ Imam Muslim collected those ahadith which are narrated by at least two narrators of all the periods right from him to that of the Prophet sws. For Imam Muslim all the narrators should not only be honest but he hould fulfill all the conditions of being a witness. In this book 218 ‘Sahaaba’ (companions) are included as narrators, whereas in Sahih al-Bukhari this number is 208.

A large number of commentaries and ‘Sharuh’ (explanations) have been written for Sahih Muslim. These include Al-Dibaj ela Sahih Muslim by Imam Jalaluddin Sauti or Sharah Muslim by Mulla Ali Qari.

The creditability of this Sahih can be judged by the opinion of some of the scholars who rate this book over Sahih Bukhari.

5 - Sunan Abu Dawood

This is the most distinguished work of Imam Abu Dawood. Some of the scholars have graded this book after Sahih al-Bukhari and Sahih Muslim. It was also narrated that Abu Dawood said: “I wrote 500,000 Ahadeeth on the authority of the Messenger of Allaah sws, I selected from them what I included in this book – meaning ‘Sunan Abu Dawood’ – I collected 4,800 Ahadeeth in it.

In his book Sunan, Abu Dawood also stated: ‘I examined the Ahadeeth on the authority of the Messenger sws and found they were [approximately] four thousand Ahadeeth, I further examined them and found that these four thousand revolve around four:

I. An Nu’maan ibn Basheer’s Hadeeth; “What is permissible is clear and what is forbidden is clear…”

II. ‘Umar’s Hadeeth; “Indeed actions are only based on intentions…”

III. Abu Hurayrah’s Hadeeth; “Indeed Allaah is good and does not accept anything except good, and Allaah ordered the believers with the same things he ordered the messengers…” and

IV. [Abu Hurayrah’s Hadeeth;] “From the proficiency of a person’s Islaam, is to leave off what does not concern him.”

He then stated; ‘Each of these four Ahadeeth is a quarter of knowledge.’

6 - Sunan al- Tirmidhi

Like others Imam also wrote several books, but the most outstanding of those is Sunan al-Tirmidhi, also called as al-Jami.

Before Imam Tirmidhi Imam Dawud Tayalisi and Imam Ahmed ibn Hanbal had compiled books that contains both authentic and weak ahadith. Later Imam Bukhari compiled his Sahih and omitted all weak narrations from it. His main objective was to derive masa'il (laws) from the relevant hadith. Later Imam Muslim compiled his book with a primary focus on the ‘isnad’ (chain of narrators). Imam Nasa'i's aim was to mention the discrepancies of the hadith whilst Abu Dawud prepared a book which became the basis for the ‘fuqaha’ (jurisprudents). Imam Tirmidhi had combined the styles of Bukhari, Muslim, Abu Dawud and Nasa'i by mentioning the discrepancies regarding the narrators and also making his compilation a basis for the jurists.

The Special characteristics of al-Jami` ut-Tirmidhi
i) It is a ‘Sunan’ and a ‘Jami`.
ii) Only 83 ahadith are repeated.
iii) Imam Tirmidhi omits the major portion of the hadith and only mentions that part which is relevant to the heading. (title)
iv) After mentioning a hadith he classifies it narration (whether it is authentic or weak, etc.)
v) He specifies the narrators names in full along with kunniya (agnomen).
vi) One hadith in Tirmidhi is a thulaathiyaat i.e. the transmitters of the hadith betwen Imam Tirmidhi and the Prophet (s) are only three.
vii) He gives an explanation to all difficult ahadith.
viii) There is no fabricated hadith in the entire book.
 

Several commentaries have been written for Jami’ al-Tirmidhi, like Qut-ul Mughtazi, compiled by Allama Jalal ad-Din Suyuti .

7 - Sunan An-Nasa’ii

Imam Ahmad Abu Abdur Rahman An-Nasa’ii wrote several books, but his collection of ahadith had an outstanding position. The initial collection of ahadith was named ‘ Sunan Kubra’, that contained both Sahih and Hasan ahadith. On the demand of the ruler of his time, he compiled another book that contained only Sahih ahadith and named it as ‘ Al-Mutaba’ or Sunan al-Sagheer or Sunan an-Nasa’ii. An-Nasa’ii contains 5270 ahadith including the repeated one. The criterion of selection of ahadith was much stricter than Imam Bukhari and Muslim, but a good number of weak ahadith are included in this book.

Several commentaries and Sharuh have been written on Sunan An-Nasa’ii, including ‘Dhuhar al-Reba ilal Mujtaba’ by Hafiz Jalaluddin Sauti.

8 - Sunan ibn Majah

Muhammad Abdullah ibn Majah had three well known books to his credit and out of these Sunan ibn Majah has the most distinguished position. It contains over 4,000 hadith in 32 ‘abwaab’ (chaptersm) divided into 1,500 sub-chapters.
Abu Zara’a Razi says,” I think that if this book reaches into the hands of the people then the other books will become irrelevant”. This book is said to have about 30 da’if (weak) ahadith. For this reason scholars puts question mark on this book. However this books stands amongst the top most authentic books of ahadith.

This book has an edge over other books with respect to its arrangement and non-repetition of ahadith. Also it has such unique ahadith that are not present in other top most books.

Several ‘Sharuh’ (explanations) have been written for this book, including ‘Sharah Sunan ibn Majah’ by Hafiz Alauddin Mughtalai (d. 762 H).

9 - Sunan al-Darimi

Imam Abdullah al- Darimi is a renowned ‘muhaddith’. Sunan al-Darimi is considered among the nine top most books of ahadith. This book of ahadith collected by Imam Darimi is known as ‘al-Musnad’ or Sunan al-Darimi. It consists of 1508 ‘abwaab’ (chapters) and 3557 ahadith. Muhaddithin have acknowledged the creditability of this book, as the reported weaknesses of the narrators are comparatively less and there are very few ‘munkir’ and ‘shadh’ ahadith in it. Its ‘isnad’ is high and number of ‘thalathiaat ahadith*’ are more as in Sahih al-Bukhari.

10 - Sahih ibn Khuzaima, Sahih ibn Hibban and Sahih Abi Awana

These three books are also graded very high after Sahih Bukhari and Sahih Muslim. Sahih ibn Khuzaima remained unavailable for some time but now it has been edited by Dr. Muhammad Mustafa Aazami, and published in 3 volumes by al-Maktab al-Islami in Beirut.

As-Sihah As-Sittah (The 6 most Authentic books of Ahadith)

The six most authentic and distinguished books of ahadith that are taught and learned in Islamic Studies are:
i) Sahih al-Bukhari
ii) Sahih Muslim
iii) Jama’i at-Tirmidhi
iv) Sunan Abu Dawood
v) Sunan Nasa’ii
vi) Sunan ibn Majah

Some of the scholar are of the opinion that The sixth book should have been Imam Malik’s al-Mawattaa insteadtead of Sunan ibn Majah. Also some scholars are of the thinking that the sixth book should have been Sunan Al-Darimi.

*thalathiaat ahadith – are those ahadith in which the number of narrators between the compiler of hadith and the Prophet sws is not more than three.