Pensamento Judaico sobre Levítico 15:19

The midrash relates to the problem of "halakhic infertility." Scripture distinguishes between two different possible types of impurity from a woman's body requiring immersion in living waters before the consummation of marital relations: Menstrual (Niddah) impurity that concludes at the end of her monthly period, When a woman has a discharge, her discharge being blood from her body, she shall remain in her impurity seven days (Leviticus 15:19); and discharge (zavah impurity, when she bleeds not during the time of her period or for more than the seven monthly days of her period. The discharge impurity concludes after seven additional clean days, which are counted after the blood has stopped: When a woman has had a discharge of blood for many days, not at the time of her menstruation... as though at the time of her menstruation, she shall be impure... When she becomes clean of her discharge, she shall count off seven days, and after that, she shall be pure (Leviticus 15:25-28). These days are called, "the seven clean days."
The Talmud mentions Rabbi Zera's testimony, according to which the daughters of Israel were stringent upon themselves to sit out "the seven clean days" for any menstrual blood that they experienced (BT, Niddah 66a). The Talmud presents a disagreement concerning the status of this stringency, whether it is a custom or a law. In practice, this stringency was accepted as law, and what that means is that women are forbidden to have sexual relations for 12-14 days a month — the 5-7 days of the monthly period and "the seven clean days." Women who ovulate during one of "the seven clean days" are unable to become pregnant, and that is why their infertility is called "halakhic infertility." Throughout the generations and into our days, various decisors have sought to permit such women to immerse even before "the seven clean days" are finished. In our days, there are some who recommend a medical solution to this problem by using hormones that delay the time of ovulation in such a way that it does not occur during "the seven clean days."

The easier the diffusion of uncleanliness is, the more difficult and the more retarded is its purification. Most easily is uncleanliness communicated by the dead body to those who are under the same roof, especially to relatives. The purification can only be completed by means of the ashes of the red heifer, however scarce it may be, and only in seven days (Num. 19:11). The uncleanness caused by a woman having running issue or during her separation is more frequent than that caused by contact with unclean objects: seven days are therefore required for their purification (Lev. 15:19, 28), whilst those that touch them are only unclean one day (ibid. 7:18). Males or females that are unclean through running issue, and a woman after childbirth, must in addition bring a sacrifice, because their uncleanness occurs less frequently than that of women in their separation. All these cases of uncleanliness, viz., running issue of males or females, menstruations, leprosy, dead bodies of human beings, carcases of beasts and creeping things, and issue of semen, are sources of dirt and filth. We have thus shown that the above precepts are very useful in many respects. First, they keep us at a distance from dirty and filthy objects; secondly, they guard the Sanctuary; thirdly, they pay regard to an established custom (for the Sabeans submitted to very troublesome restrictions when unclean, as you will soon hear); fourthly, they lightened that burden for us; for we are not impeded through these laws in our ordinary occupations by the distinction the Law makes between that which is unclean and that which is clean. For this distinction applies only in reference to the Sanctuary and the holy objects connected with it: it does not apply to other cases. “She shall touch no hallowed thing, nor come into the Sanctuary” (Lev. 12:4). Other persons [that do not intend to enter the Sanctuary or touch any holy thing], are not guilty of any sin if they remain unclean as long as they like, and eat, according to their pleasure, ordinary food that has been in contact with unclean things. But the practice of the Sabeans, even at present general in the East, among the few still left of the Magi, was to keep a menstruous woman in a house by herself, to burn that upon which she treads, and to consider as unclean every one that speaks with her: even if a wind passed over her and a clean person, the latter was unclean in the eyes of the Sabeans. See the difference between this practice and our rule, that “whatever services a wife generally does to her husband, she may do to him in her separation”; only cohabitation is prohibited during the days of her uncleanness. Another custom among the Sabeans, which is still widespread, is this: whatever is separated from the body, as hair, nail, or blood, is unclean; every barber is therefore unclean in their estimation, because he touches blood and hair; whenever a person passes a razor over his skin he must take a bath in running water. Such burdensome practices were numerous among the Sabeans, whilst we apply the laws that distinguish between the unclean and the clean only with regard to hallowed things and to the Sanctuary.