Book: Siyar A'lam An-Nubala by Ad-Dhahabi - سير أعلام النبلاء ـ الإمام الذهبي

The First Class

The individuals of the first class are mentioned in his book for those who carefully consider the chapters. The second class comprises people about whom some have spoken critically, while others have commended them. Their narrations are excluded if they have been weakened or accused of heresy, as was also done by Al-Bukhari.

Statement by Qadi Iyad

Qadi Iyad then said: In my opinion, he included three classes in his book and omitted the fourth class.

Explanation by Al-Dhahabi

Al-Dhahabi commented (10/182-183):

I say that he indeed included the hadiths of the first class and most of the second class, except for a small number that he found objectionable from the second class. He then included some hadiths from the third class, but not many, for corroboration and secondary evidence. Rarely did he include any of their hadiths in the main core. If all the hadiths of this class were included in "Sahih," the book would double in size, which would lower its rank of authenticity. They are like 'Ata ibn al-Sa'ib, Layth, Yazid ibn Abi Ziyad, Aban ibn al-Sa'ib, Muhammad ibn Ishaq, Muhammad ibn 'Amr ibn Alqama, and a group like them. He only included a single hadith when it had a basis, while Ahmad in his "Musnad," Abu Dawood, An-Nasa'i, and others mention more of their hadiths. When they include hadiths of weak narrators from the fourth class, they select them without full coverage, based on their opinions and judgments.

The Fifth Class

As for the fifth class, which consists of those unanimously dismissed and abandoned for their lack of comprehension and accuracy, or for being suspected, rarely do Ahmad and An-Nasa'i include them. Abu 'Isa mentions them sparingly with clarification. Ibn Majah includes a few hadiths from them without explanation. Abu Dawood seldom includes them, but when he does, he often provides clarification.

The Sixth Class

The sixth class includes extremist Rafidis, missionary Jahmis, liars, fabricators, and those abandoned and discredited, like 'Umar ibn Subh, Muhammad ibn Al-Maslub, Noah ibn Abi Maryam, Ahmad ibn al-Jawibari, and Abu Huthaifah al-Bukhari. They have no place in books except 'Umar, for whom Ibn Majah included one hadith (1), which was an error. Similarly, Ibn Majah included a single hadith for Al-Waqidi, but he masked his name and generically referred to him (2).