LEV168 The Torah, in a number of places, describes the notions of tu'mah (ritual impurity or unfitness) and toharah (ritual purity or fitness). The state of tum'ah is contracted in a variety of ways: eating non-kosher animals, coming into contact with a corpse, becoming ill with a disease often translated as leprosy (that was most certainly not like the leprosy we know today), or having particular body emissions. One could also contract tum'ah by coming into certain forms of contact with someone else who was tameh (the mail adjectival form of the noun tum'ah) or te'mei'ah (the female adjectival form). Generally speaking, this state was of little consequence, except for the critical fact that, during the biblical era, one who was in a state of tum'ah was unable to offer sacrifices at the ancient Jerusalem Temple. Menstruation was one of a number of general emissions that could cause a person to contract tum'ah; male ejaculation and either male or female irregular "flux" emissions (from illness, miscarriage, and so forth) also did so. Tum'ah could be contracted from another person, and though in Leviticus 15 the consequences of this contraction are described in the simple language of cause-and-effect, the Torah (Leviticus 18:19; 20:18) twice explicitly prohibits sex with a menstruant. During the Rabbinic era, normal menstruation and irregular "flux" states became conflated, as the Rabbis decreed that a woman must--as the Torah commands for a woman with an irregular "flux" [this verse]--wait an extra week after the cessation of her regular menstrual period (B. Niddah 66a). By the time of the Mishnah, it is also simply presumed that a menstruant must immerse in water before she would once again be permitted to engage in sexual relations, as the Torah obligates one who experienced an irregular "flux" emission from illness, miscarriage, or some other non-typical occurrence to immerse in water before resuming sexual relations.(Leviticus 15). As such, according to post-Rabbinic traditional practice, a couple does not engage in sexual relations while a woman is menstruating (which, according to Ashkenazi practice, lasts a minimum of five days) and for seven days thereafter. At the end of this period, she immerses in the ritual bath and is once again permitted to engage in marital relations with her husband. This practice of sexual separation during menses has been controversial among many feminists. There are those who repudiate the practice entirely, such as Rachel Adler… other feminists, such as Haviva Ner-David, find beauty and "spiritual power" in the notion of ritually marking the body's cycles and the sexual ebb and flow in her marriage. (By Danya Ruttenberg, "Jewish Sexual Ethics")