"And do not marry polytheistic women until they believe. And a believing slave woman is better than a polytheist, even though she might please you."
What the verse says
Muslim men may not marry polytheist women; Muslim women, by the classical consensus derived from Q60:10 and Q5:5, may not marry any non-Muslim man at all. The interfaith marriage rules are asymmetric by sex.
Why this is a problem
Kecia Ali, in Sexual Ethics and Islam (Oneworld, 2006), covers the sex-asymmetric interfaith marriage rules and documents that Muslim men may marry Christian or Jewish women while Muslim women may not marry any non-Muslim man under any circumstances. Leila Ahmed, in Women and Gender in Islam (Yale, 1992), documents how Q2:221's interfaith marriage prohibition was applied asymmetrically by classical jurisprudence across all four Sunni schools without exception. The asymmetry is scripturally encoded: Q5:5 explicitly permits Muslim men to marry women from the People of the Book; no equivalent permission exists for Muslim women. The verse's own internal comparison creates additional tension — 'a believing slave woman is better than a free polytheist' — inverting the normal social hierarchy by religion, yet the same verse elsewhere maintains the free-woman preference by economic status. The egalitarian religious inversion coexists with class stratification without resolution.
The Muslim response
Muslim scholars argue that the asymmetric rule reflects a structural reality: under classical Islamic marriage law, a husband's religion governs the household's religious life, the religious upbringing of children, and the wife's practical freedom of worship. Permitting Muslim men to marry People-of-the-Book women was deemed safe because Islamic law required the husband to permit his wife to practice her religion; permitting Muslim women to marry non-Muslim men was deemed unsafe because a non-Muslim husband would not be bound to the same obligation. The rule is read as protective of Muslim women's religious practice, not as a discriminatory restriction. Contemporary scholars including Tariq Ramadan argue the rule was always contextually grounded in household-authority structures that modern Muslim states can revise.
Why it fails
The household-authority justification frames the restriction in terms of male authority over wives — which is itself the problem: a rule that restricts women's marriage options because they would be subject to their husband's authority operates on a patriarchal premise that compounds the original concern. The sex-asymmetric interfaith rule is the precise point Ali and Ahmed document — Muslim men may marry out, Muslim women may not — and that specific asymmetry is scripturally encoded across the Sunni tradition without exception. The contemporary scholars who argue for revision are acknowledging that the rule's premise is unacceptable; they are not reading the text in its favor. And the verse inverts hierarchy by religion while maintaining it by class — subordinating social standing to faith — which exposes the patriarchal and class assumptions the rule encodes.