Question: Why do religious Jewish women have to wear skirts? Why isn’t a married woman supposed show her hair? Is this connected to a particular Mitzvah (Commandment)?
Answer: There are several aspects to Tznius—modesty in dress and deed. One aspect is the codification of exactly what may and may not be uncovered. There are laws of modesty for both men and women, but I will address only the laws for women right now. For a woman, the minimum standard is that her neckline must not be lower than her collarbone, her sleeves must come past her elbows and her skirt must fall below her knees. For a married woman there is an additional requirement, namely, that her hair must be covered.
You ask if these rules have a connection to Mitzvos. The answer is that the laws of modesty ARE mitzvos and that a woman gains great spiritual heights—and immense reward—for keeping these Mitzvos, the same as any other Mitzvos of the Torah.
The above rules apply mainly when a woman is in public. In the presence of other women, in a private place, a woman does not have to be covered up. So, for example, if she is swimming with other women she can wear a bathing suit. If she is exercising at an all-women’s gym, she can wear shorts. If she has a baby, she can nurse her baby in the presence of other women, and in the presence of her husband and children. For a married woman, her hair does not have to be covered in the presence of her husband and children. In your own home you can wear pajamas, as long as outsiders are not present. These are only a few examples, to give you an idea. For details, you need to study more.
In addition to these codified laws, there is also a concept of Tznius having to do with modesty in taste and deportment. A woman might be completely covered up—fulfilling the letter of the law—and yet she might, for example, be wearing a very tight, brightly colored and eye-catching dress, covered all over with sequins. This would certainly be immodest!
So much has to do with a woman’s innate sense of good taste and dignity, that it is hard to spell out completely exactly what is and what is not modest. It also depends partly on what is accepted in society. For example, if you were living in Victorian England where women wore skirts to the ground, a skirt falling just below the knee would not be modest.
In regard to why a woman must wear a skirt or dress, there are a number of reasons. The most important is that a woman is not allowed to wear men’s clothing (nor is a man allowed to wear women’s clothing). (See Deuteronomy 22:5)
Although nowadays pants are made for women, they were originally men’s clothing and still closely resemble men’s clothing. There is a tendency in society these days for women to try to act like men, and wearing clothing that resembles men’s clothing seems to be part of this trend. We don’t find men wearing dresses and togas.
When a woman is wearing pants, she can walk and sit in a masculine way—e.g., with the ankle of one leg crossed over the knee of the other. We have become so used to this that we don’t perceive it as masculine or immodest, but if you think about what a woman looks like when she sits this way, you will see what I mean.
Besides the prohibition on wearing men’s garments, there is also the fact that pants show the shape of a woman’s body more than does a skirt or dress. Many authorities do permit wearing pants to protect a girl from the cold or to allow her to go hiking—provided that she wears a skirt over the pants. If you live in a place like India where typical women’s clothing is loose, baggy pants worn under a long robe—then that is acceptable.
The Torah idea of modesty, by the way, is NOT that a woman should look ugly and dowdy. Not at all! All of the Matriarchs in the Torah—Sarah, Rivka, Leah and Rochel—are described as beautiful women. Ideally a Jewish woman will wear pretty clothes and will always look well-groomed and tastefully dressed. However, at the same time, we want to de-emphasize sexual attractiveness outside of marriage. Instead we want others to focus on our other qualities, qualities of intelligence, character and so on. A woman should not be available, or look available, to every passing man in the street. Our idea of modesty has a strong component of privacy and dignity. Dressing to arouse sexual desire is only appropriate within the confines of marriage, when it is indeed very positive.
As for hair covering, this is an extra dimension of privacy, dignity and modesty that is required of married women. The source of this Mitzva is the verse in Numbers 5:18 dealing with the case where a woman has been alone with a man under circumstances which arouse her husband’s suspicion that she may have committed adultery. Part of the ceremony she must undergo to test her innocence involves the Kohen (Temple priest) uncovering her hair, to embarrass her, from which the Sages deduced that normally, a married woman’s hair would be covered, and it would be embarrassing for her to be seen in public with her hair uncovered.
Precisely because a married woman is sexually experienced and is more mature and in some ways more alluring than a single girl, precisely for that reason, she has to take extra steps to dress modestly. Hair covering is part of that extra care. It tells people at a glance that she is a married woman and is not available to other men. Many women wear attractive wigs (Sheitels) and some people ask, “If the Sheitel looks so much like her own hair, what’s the difference?” But the fact is, within the religious community, even the most attractive Sheitel can be spotted instantly and gives the message that this woman’s status is different from that of a single girl.
There is a really excellent book that I highly recommend on this subject. It’s called Inside/Outside, by Gila Manolson, and it is very insightful and inspiring.