And it is taught in a baraita: If one moves the discharge seen by a zav on the first day, Beit Shammai say: Due to the uncertainty, his status of ritual purity is contingent upon whether he sees another emission. If the zav sees a discharge a second time he will retroactively have been a full-fledged zav and his discharge renders one who moves it impure. But if he does not see another discharge he will remain like one who experienced a seminal emission, which means that his discharge does not render one who moves it impure. And Beit Hillel deem him pure. The discharge has the status of a seminal emission and does not transmit impurity to one who moves it.

The baraita continues: With regard to items designated for lying or sitting and their status between the first sighting and the second sighting, Beit Shammai say: Due to the uncertainty their status of ritual purity is contingent upon whether he sees another emission, and Beit Hillel deem them pure.

Abaye explains Rav Kahana’s difficulty with Rav Huna’s opinion: It is taught in the first clause of the baraita that if a man sees one sighting of ziva, Beit Shammai say: His status is like that of a woman who observes a clean day for a day she experiences a discharge. Apparently, according to the opinion of Beit Shammai the ritual purity status of a woman who observes a clean day for a day she experiences a discharge is contingent upon whether she experiences an emission of blood. This is difficult for Rav Huna, who explains that Beit Shammai hold that a woman who observes a clean day for each day of discharge is definitely impure, by rabbinic law.

The Gemara answers that Rav Huna would explain: Do not say that his status is like that of a woman who observes a clean day for a day. Rather, say that he is like one who engages in intercourse with a woman who observes a clean day for a day after she has immersed. Rav Huna agrees that items designated for lying or sitting that this man sits or lies on is ritually impure only if she experiences bleeding before the end of the day.

The Gemara asks: What is different with regard to him, a man who engages in intercourse with a woman who is observing a clean day for a day, that he does not transmit impurity to items designated for lying or sitting, and what is different with regard to her, that woman herself, that she does transmit impurity to items designated for lying or sitting?

The Gemara explains: With regard to him, as he does not frequently see blood, the Sages did not issue a decree rendering him impure to such an extent, if the woman has not seen blood on the second day. Whereas with regard to her, as she does frequently see blood, the Sages did issue a decree rendering her definitely impure to this degree.

The Gemara further inquires: And since a decree was applied to her, as she commonly sees blood, what is different with regard to items designated for lying or sitting, that she transmits impurity to them, and what is different with regard to the one who engages in intercourse with her, that she does not render him impure?

The Gemara answers: With regard to items designated for lying or sitting, she renders them ritually impure because she frequently sits or lies on them, whereas with regard to one who engages in intercourse with her, which is not nearly as frequent, she does not render him ritually impure.

The Gemara raises another difficulty with regard to Rav Huna’s opinion. We learned in the mishna: If she saw blood on the eleventh day and observed part of a corresponding clean day and immersed on the day following the day that she saw blood and engaged in intercourse with her husband, that is wayward conduct, as the possibility exists that she will experience bleeding after intercourse that will be appended to the bleeding of the previous day, rendering her a zava and disqualifying the immersion.

The mishna adds: And the status of ritually impure items with which they came into contact and the status of their intercourse is contingent upon whether she experiences bleeding on the day of her immersion. The Gemara explains the difficulty. What, is it not correct to say that all, i.e., Beit Shammai and Beit Hillel, agree with this clause of the mishna? If so, Beit Shammai concur that this woman renders items impure only due to uncertainty. This is not in accordance with the statement of Rav Huna.

The Gemara answers: No, this clause of the mishna is only in accordance with the opinion of Beit Hillel. As it is taught in a baraita that Rabbi Yehuda said to Beit Hillel: Do you call this type of behavior wayward conduct? But he intended only to engage in intercourse with a menstruating woman. The Gemara questions the meaning of Rabbi Yehuda’s statement. Can it enter your mind that he intended to engage in intercourse with a menstruating woman? The mishna and baraita are not referring to a man who engages in intercourse with a menstruating woman.

Rather, say that Rabbi Yehuda meant that this man intended only to engage in intercourse with a zava. The Gemara rejects this formulation as well: Can it enter your mind that Rabbi Yehuda said he intended to engage in intercourse with a zava? The mishna and baraita are not referring to a man who engages in intercourse with a zava either. Rather, say that Rabbi Yehuda meant that this man intended to engage in intercourse with a woman who observes a clean day for a day she experiences a discharge. This baraita indicates that the latter clause of the mishna is only according to the opinion of Beit Hillel, as Rabbi Yehuda directed his comments specifically to them.

§ The Gemara cites another discussion concerning a woman who experiences bleeding toward the end of her eleven days of ziva. It was stated with regard to a woman who experiences bleeding on the tenth day of her eleven days of ziva, that Rav Yoḥanan says: The tenth day is considered like the ninth, i.e., just as the ninth day requires the observance of a day clean from discharges on the following day, so too does the tenth day require observance of a day in case she experiences bleeding on the eleventh day.

Reish Lakish says: The tenth day is considered like the eleventh day, as in such a case it is impossible for her to experience bleeding for the three consecutive days within the eleven days of ziva. Just as the eleventh day does not require the observance of a day clean from discharges, so too the tenth day does not require the observance of a day clean from discharges, since even if she experiences bleeding on both the eleventh and the twelfth days, the last of the three consecutive days was already the start of her days of menstruation, and therefore she does not become a greater zava.

There are those who teach the dispute between Rabbi Yoḥanan and Reish Lakish with regard to this case: Rabbi Elazar ben Azarya said to Rabbi Akiva: Even if you were to amplify and derive halakhot from the repeated terms “in oil,” “in oil,” stated with regard to the thanks offering (see Leviticus 7:12) for the entire day, I would not listen to you and accept your claim. Rather, the halakha that one-half of a log is the requisite amount of oil for the thanks offering, and the halakha that one-quarter of a log is the amount of wine for a nazirite, and the halakha that a woman who experiences an emission of blood during the eleven days that are between one period of menstruation and the next period of menstruation is a zava, each of these is a halakha transmitted to Moses from Sinai. None of the halakhot are derived from verses.

The Gemara asks: What is the halakha mentioned here with regard to the eleven days between one period of menstruation and the next? Rabbi Yoḥanan says: It is referring to the halakha that distinguishes the first ten days from the eleventh day. Reish Lakish says: It is referring to two halakhot that distinguish the first ten days from the eleventh.

The Gemara elaborates: Rabbi Yoḥanan says that this is referring to the halakha which distinguishes the first ten days from the eleventh. It is the eleventh that does not require the observance of a day clean from discharges, but for the other ten days she must perform observance. And Reish Lakish says: It is referring to two halakhot that distinguish the first ten days from the eleventh. The eleventh day does not require observance, and it does not serve as a day of observance for the tenth day, i.e., the tenth day also does not require observance. The tenth day does not require observing since day eleven is excluded from being a day of observation for the previous day.

The Gemara raises a difficulty with regard to Rabbi Elazar ben Azarya’s claim that the eleven days of ziva is a halakha transmitted to Moses from Sinai. Are these halakhot transmitted to Moses from Sinai? Not so; rather, these are derived from verses. As it is taught in a baraita: One might have thought that one who sees blood for three consecutive days at the beginning of the days of menstruation will be a zava and is required to count seven clean days and to bring an offering afterward (see Leviticus 15:28–30).

And if so, how do I realize the meaning of the verse: “And if a woman has a flow, and her flow on her flesh be blood, she shall be in her impurity seven days; and whoever touches her shall be impure until the evening” (Leviticus 15:19)? This is referring to one who sees blood on only one day. But perhaps one who sees blood for three days at the beginning of her days of menstruation should become a zava? The verse states: