and if creation had begun on Saturday and ended on Friday, it would have taken seven days, contrary to what the Quran states. Moreover, expert hadith scholars establish that this hadith is defective on other grounds, showing that a particular narrator’s version is mistaken for reasons they explain. This is what is called knowledge of hidden defects in hadith: a hadith’s chain of transmission may appear sound, yet other evidence reveals that its narrator mistakenly attributed it to the Prophet when it actually stopped at a Companion, supplied a connected chain when it was in fact disconnected, or confused one hadith with another.

This is a distinguished discipline. Yahyā ibn Saʿīd al-Ansārī, then his associate ʿAlī ibn al-Madīnī, and then al-Bukhārī were among its most knowledgeable scholars, as were Imam Ahmad, Abū Hātim, al-Nasāʾī, al-Dāraqutnī and others. Well-known works have been written on it.

Even in al-Bukhārī’s own collection, there are three hadiths whose authenticity some have disputed. One example is the hadith of Abū Bakrah, who reported that the Prophet, may Allah bless him and grant him peace, said of al-Hasan:

“This son of mine is a leader, and through him Allah will reconcile two great groups of Muslims.”

A number of scholars, including Abū al-Walīd al-Bājī, disputed al-Bukhārī’s judgment, claiming that the narrator al-Hasan had not heard this hadith from Abū Bakrah. But al-Bukhārī is correct: al-Hasan did hear it from Abū Bakrah, as has been explained elsewhere. This has also been established elsewhere. Al-Bukhārī is more skilled and experienced in this discipline than Muslim; for this reason, they never agree on