Popular Muslim custom elevated circumcision beyond the importance Muhammad gave it

Evidence

The prohibition of certain foods, particularly pig, and of wine, in certain writers gave rise to picturesque or curious legends to explain their origins. Here the interest of Christians only reflects the popular practice of Muslims; some food prohibitions, notably that of swine’s flesh, have always been taken very seriously by Islam; and the customs of the populace have given circumcision an importance that Muhammad never did. Strictly, circumcision is related to ritual purity, and the rules governing food to questions of impurity; but these matters were never discussed in connection with ablutions, or in the course of any general discussion of religious impurity; no such impurity apart from actual sin was recognised by Christians. — Norman Daniel, Islam and the West, 1268

Categorization

• QUESTION: Worth chasing: the claim that Christian observers never discussed ritual impurity in connection with ablutions because they recognized no impurity apart from sin — this is a striking theological claim about the conceptual gap between Christianity and Islam on purity that deserves verification and expansion.
• SEED: Angle: ‘Purity for dummies’ — how a faith whose core taxonomy of impurity (jinn, ritual dirt) simply had no Christian analogue forced early modern polemicists to invent absurd explanations, and how those invented legends then hardened into ‘facts’ passed down for centuries.