Midrash su Levitico 15:33

1) (Vayikra 20:18) ("And a man who lies with a woman in her flow and reveals her nakedness — he has bared her fountain and she has revealed the fountain of her blood; and both of them shall be cut off from the midst of their people.") "And a man": to exclude a minor. "who lies with a woman in her flow" (davah): "davah" is "niddah," as it is written (Vayikra 15:33) "And she who flows (davah) with her niddah flow, and he who flows with his discharge."

“For this our heart suffers; for these our eyes are dim” (Lamentations 5:17).
“For this our heart suffers.” Rabbi Simlai said: The Holy One blessed be He gave great suffering to this woman, as after she observes the days of her menstruation she then observes the days of her ziva.²³By Torah law, when a woman menstruates she is impure for seven days. During that time, it is also forbidden for her to engage in intercourse with her husband. If she experiences a discharge of blood in the eleven days following the seven days of menstruation, she has the status of a zava and is impure for one additional day. If she discharges blood for three consecutive days during this period of eleven days, she must observe seven clean days without discharge before she may become pure. This is a cause of suffering for women, as indicated by the verse: “And one who suffers through her menstruation” (Leviticus 15:33). Rabbi Elazar son of Rabbi Yosei HaGelili says: This woman, because she separates from her husband for two or three days, the Torah calls her suffering. That is what is written: “And one who suffers through her menstruation” (Leviticus 15:33). We who departed from our eternal House, from our Temple, for many days and many years, all the more so that we are called suffering. That is why it is stated: “For this our heart suffers.” For what? It is “for these our eyes are dim.”²⁴“For Mount Zion that is desolate.”

9) (Vayikra 15:33) ("And (of) her who flows with her menstrual flow, and (of) him who flows with his (zov) discharge, for male or female, and (of) him who lies with her who is unclean.") "And (of) her who flows with her menstrual flow, and (of) the zav" (of two sightings), who, like a niddah, confers tumah upon mishkav and moshav (and who requires the counting of seven days). And, (even more than a niddah), he requires running water (for his cleansing). And he is not obligated to bring an offering. "the law of the zav (of one sighting) and the zav (of two sightings) his zov" (the zav) of three sightings: This is the confirmed zav, who confers tumah upon mishkav and moshav, who requires running water, and who is obligated to bring an offering.