The methodological foundations that caused the later generations to abandon the Sunnah:

What, then, are the principles and maxims that those who came after the early Muslims devised, which diverted them from studying and following the Sunnah? In answer I say:
They may be summed up in the following points:

First: The claim made by some scholastic theologians that a solitary report (ḥadīth al-āḥād) does not establish—