In Judaism, the ancient laws of impurity in regard to menstruation are known as the laws of niddah, and their realized form as the ritual of impurity, niddah. These laws continue to retain their symbolic power, with a shift in meaning from a state of impurity related to sacrificial rites to a state of impurity related to sexual prohibitions in the private family sphere. This means that, during a period of 14 days, the Jewish woman must avoid any sexual contact with her husband. Based on textual and contextual analysis of manuals which teach and explain to women the practice of niddah, we claim that, with the establishment of the modern state of Israel the meaning of niddah has been expanded to the public national domain. Religious Zionism in Israel has enlisted the experiences of menstrual defilement and purification to the Jewish struggle over national boundaries and collective identity. Women are told that by practicing niddah, they take on responsibility not only for purity of the family, but also for the people of Israel, the Land of Israel, and the preservation of the holy scriptures, the Torah. This rhetorical linkage politicizes both the body of women and the practice of niddah. In fact, the practice has become a discourse of national revival.