There are few aspects of Jewish observance which elicit more disagreement than the subject female hair covering. Sometimes, I walk through the Mea Shearim district of Jerusalem, which has one of the highest concentrations of observant Jews in the world, and I see hats that cover the entire head, part of the head, snoods, scarves, wigs, hats or scarves on top of wigs—basically, every combination of hair covering you can imagine. The variation of viewpoints on this practice is staggering, and often, one can tell with which movement in Orthodoxy a woman is aligned with based on the way in which she covers her hair.
It is a tradition for all married women to cover their hair. This commandment is based on a description in the Torah of a ritual that must be undertaken by a woman who is suspected of adultery. She must go to the Temple and give an offering. The priest uncovers her hair, which, of course, indicates that her hair was covered in the first place. The uncovering of the suspected woman’s hair is considered to be a humiliating experience, which means that a woman usually has her hair covered. Based on this source, there is a vast array of viewpoints on how the hair should be concealed.
Many women wear scarves, although the front part of their hair can be seen. This revealed portion is called a “tefach” which is the maximum amount of hair that can be shown. Some rabbis rule that, in public, even a tefach should not be revealed, and encourage women to ensure that all of their hair is covered. Many rabbis, including the “Rebbe” Menachem Mendel Schneersohn, have said that a wig is the best way to cover all of a woman’s hair. Rabbi Ovadia Yosef, the spiritual leader of Shas, has forbidden the use of wigs, saying that they are often more attractive than a woman’s natural hair, and are immodest. Supporters of wig-wearing say that the mitzvah is concerned with making sure that the hair is covered and not that a woman should look less attractive. They also have Kabbalistic (mystical) reasons for ensuring every strand of hair is covered, as well as concealing the hair for the sake of modesty.
The practice of head shaving is limited to certain Chassidic groups and is not widespread. These women cut all of their hair off and then cover their heads with wigs and hats or scarves. They want to ensure that their hair is never seen, but some object that, if a woman has no hair, she has nothing to cover. The battles over hair covering are “covered” masterfully by Lynn Schrieber in her book “Hide & Seek: Jewish Women and Hair Covering” available at Urim publications