“In my Jewish family, and I’m sure in many other Jewish families, when the girl got her period, the mother would slap the girl across the face, very hard, and leave an imprint. I’m not sure what the reason was… something about warding off evil spirits, I think. To keep the devil away from you.”
When a girl begins to menstruate, she is able to get pregnant. This can be a great worry for many mothers who are trying to keep their children pure for marriage, or, at least, keep their children from becoming mothers before they are ready. The slap is supposed to be painful so that it warns you against becoming pregnant; the pain of the slap is symbolical of the pain of pregnancy and the difficulty of raising a child. Furthermore, being pregnant at a young age is like a slap in the face to your family. An unwed, pregnant girl would bring great shame to a traditional Jewish family. The sting of the slap, on one level, represents that sting of shame that the family would feel. The slap is supposed to leave an imprint for a while so that it serves as a lasting reminder not to get pregnant.
Judaism in its institutional form does not tend to deal with spirits or concepts such as the devil, so it is interesting that this Jewish folk practice invokes those ideas. This practice is an example of how folk traditions can deviate from a religion’s scripture or institutionalized forms.