This makes clear that they were people of knowledge and certainty, not ignorance and blind imitation, and that they attained certain, immediate knowledge through Allah’s guidance and His opening their hearts. This has been explained at length elsewhere, where it was shown that faith and knowledge do not depend on the rational inquiry introduced by the speculative theologians, let alone discourse that contradicts the revealed texts.

And his statement:

“They saw that their knowledge of the Book and Sunnah amply sufficed them, leaving them no need for anything else.”

This is because the Book and Sunnah have explained the truth and the ways by which it is known. They contain rational proofs and illustrative examples—which constitute demonstrative reasoning—that are more effective in attaining knowledge and certainty than what the innovators among the speculative theologians and philosophers have introduced.

The Book’s guidance does not consist merely in conveying reports, as some suppose. Rather, it has drawn attention to, explained, and indicated the evidence, proofs, and means of attaining knowledge and certainty through which truth is distinguished from falsehood. This has been explained at length elsewhere.

As for his account of how, as time went on and some people’s resolve to seek a thorough understanding of the knowledge contained in the Book and Sunnah weakened, they began refuting the specious arguments of the heretics