Assalaamu alaykum. I want to ask a question regarding hadith In some books - such as al-Haakims 'al-Mustadrak' - the compiler says that the hadeeth meets the criteria of al-Bukhaari or Muslim or them both. What is actually meant by this? As far as I have understood, when it is according to their criteria, it means that the men of the chain are men they (al-Bukhaari and/or Muslim) have included in their Saheeh books. Is this correct? And are there other factors that make the hadeeth according to the criteria of one or two of them? May Allaah reward you with goodness.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

Many of the Hadeeth scholars hold that the meaning of Al-Haakim’s statement, ‘meets the criteria of Al-Bukhari or Muslim or both of them’ is that Imaam Al-Bukhari and/or Muslim presented Ahaadeeth reported on the authority of the narrators in that chain of transmission. This is the opinion of Ibn As-Salah, An-Nawawi, Ibn Daqeeq Al-'Eed, and Ath-Thahabi. Al-‘Iraaqi explained that statement as follows: “It means that the narrators in this chain of transmission are as trustworthy and accurate as the narrators on whose authority Al-Bukhari and/or Muslim reported Ahaadeeth.”

The first opinion is more likely to be the correct one because it is supported by Al-Haakim’s commentary on the authenticity of the Ahaadeeth in his book, Al-Mustadrak. Al-Haafith Ibn Hajar wrote, “When the Hadeeth narrators are accepted by Al-Bukhari and/or Muslim (i.e. when they present Ahaadeeth reported on the authority of those narrators), he (Al-Haakim) would comment on the Hadeeth, 'Saheeh (sound) according to the criteria of Al-Bukhari and/or Muslim'. If Al-Bukhari and Muslim did not present a Hadeeth narrated on the authority of some of the narrators of the Hadeeth, he would comment, 'Saheeh chain of transmission'.” [An-Nukat 'ala Muqaddimat Ibn As-Salah]

Allaah Knows best.