The foremost work in authenticity is al-Bukhārī’s book. It contains no hadith text known to have been reported incorrectly from a Companion, although some errors occur in the wording of hadiths. Within his Sahīh itself, al-Bukhārī has included material that makes the transmitter’s error clear, as when he explains the transmitters’ differing accounts of the price of Jābir’s camel. It also contains reports from some Companions that are said to be mistaken. For example, it reports from Ibn ‘Abbās:

“The Messenger of Allah, may Allah bless him and grant him peace, married Maymūna while in a state of pilgrimage consecration.”

The widely accepted account among most people is that he married her while not in that state. It also reports from Usāma:

“The Prophet, may Allah bless him and grant him peace, did not pray inside the Kaaba.”

Yet it reports from Bilāl that he did pray inside it, and scholars regard this latter account as more authentic.

As for Muslim’s collection, it contains wordings known to be erroneous, such as:

“Allah created the soil on Saturday.”

Al-Bukhārī explained that this is an error and that these are actually the words of Ka‘b. It also reports that:

“The Prophet, may Allah bless him and grant him peace, performed the eclipse prayer with three bowings in each unit of prayer.”

The correct account is that he performed the eclipse prayer only once. It also reports that Abū Sufyān asked him to marry Umm Habība, and this is an error.

This is among the most distinguished branches of hadith scholarship, known as the study of defects in hadith.

As for Hilyat al-Awliyā’, it is among the finest works by later authors on accounts of ascetics. It contains some anecdotes that it had no need to include, and many of the hadiths transmitted in its opening sections are weak—indeed, fabricated.