While a wife’s obligations to her husband are largely of rabbinic origin, the Torah commands a man to clothe and support his wife. The pasuk commands: “She’era, kesuta ve-onata lo yigra – a husband may not withhold basic family needs from his wife,” (Shemot 21:9-10).
The precise definitions of these terms are discussed in our Gemara. Rabbi Eliezer ben Ya’akov, for example, is quoted as interpreting she’era kesuta as a single term that means that appropriate clothing must be made available to her, so that new, warm clothing should not be given in the summer, nor cool, well-worn clothing in the winter. Similarly, a young woman should not be given clothing appropriate for an old woman, nor should an elderly woman receive a young woman’s clothing.
Although there is some disagreement about which of the terms teaches that engaging in normal sexual relations is obligatory for the husband (Rabbi Elazar points to the passage in Vayikra 18:6 to suggest that it is the word she’era, while Rava identifies it as onata based on the passage in Bereishit 31:50), it is clear that a regular sexual relationship is a Biblical requirement. In this context, Rav Yosef taught a baraita that appears to understand the word she’era as requiring a “closeness of the flesh” during relations, thus forbidding the “Persian tradition” of engaging in sexual relations while dressed. Rav Huna, in fact, rules that a husband who insists that sex take place while wearing clothing can be compelled to offer his wife a divorce and pay her the ketuba.
Some point to a Gemara in Massekhet Berakhot (8a), where a number of positive Persian customs are mentioned. Among those customs is that they are tzanu’a – modest – while engaged in sexual relations, which seems to view such behavior as praiseworthy. The Magen Avraham (Shulḥan Arukh, Orah Hayyim 240:8) grapples with this question and concludes that if both husband and wife agree to have sex while dressed, then it is considered a higher level of modesty. However, as the Ritva argues, if only the husband perceives this as modesty, it can be grounds for his wife to demand a divorce.