The Gemara asks: According to Rabbi Ḥiyya, who teaches that this case incurs sixteen sin-offerings, who is this tanna who holds that a prohibition takes effect where another prohibition already exists for a more inclusive prohibition, an expanded prohibition, and a simultaneous prohibition? If these men are brothers, the moment that one betrothed a woman, that woman was immediately rendered forbidden to the second brother both as a married woman and as his brother’s wife. When the second brother betrothed her sister, this added the prohibition pertaining to his wife’s sister. This is a more inclusive prohibition because, as a result of this betrothal, the second brother is prohibited from engaging in sexual intercourse not only with his wife’s sister, who is his brother’s wife, but also with all of her other sisters. When this woman becomes a menstruating woman, she is forbidden to her husband as well, which is an expanded prohibition. Consequently, the mishna includes examples of all three types of prohibitions and asserts that they all take effect in this case. Therefore, the Gemara wonders which tanna holds that in each of these cases the prohibition takes effect even where another prohibition exists.

Rav Yehuda said that Rav said: This is the opinion of Rabbi Meir, as it is taught in a baraita: There is one who performs a single act of eating an olive-bulk of food, and he is liable to bring four sin-offerings and one guilt-offering.

How so? This halakha applies to one who is ritually impure who ate forbidden fat that was notar from a consecrated offering, i.e., it remained after the time when it was permitted to eat it, and this occurred on Yom Kippur. One who did this is liable to bring one sin offering for eating consecrated food while impure, one for eating forbidden fat, one for eating notar, and one for eating on Yom Kippur. He is also liable to bring a guilt-offering for misuse of consecrated items. In this case, it was prohibited to eat the fat from the moment the animal was born. When the animal was consecrated, the prohibition against deriving benefit from it took effect on the entire animal, rendering this an expanded prohibition. When the priest became ritually impure and thereby prohibited from partaking of all sanctified foods, a more inclusive prohibition took effect. The moment the fat was rendered notar, it became prohibited to offer it on the altar as well, so that that is another instance of an expanded prohibition. Lastly, on Yom Kippur, an additional, more inclusive prohibition took effect because on Yom Kippur it is prohibited to eat all food, even that which is not consecrated.

Rabbi Meir says: There is one more sin-offering for which he may be liable. If it was Shabbat and he carried this olive-bulk of food from one domain to another in his mouth, he is liable for carrying out on Shabbat. The Rabbis said to Rabbi Meir: Liability for the sin-offering that you added is not incurred from violation of the same type of prohibition. He is liable for carrying out the food, not for eating it. In this example, the prohibitions of Shabbat and Yom Kippur take effect at the same moment, and therefore this last case would be an instance of simultaneous prohibitions, and Rabbi Meir holds that they take effect as well. Therefore, this baraita demonstrates that Rabbi Meir holds that prohibitions take effect where other prohibitions already exist in all of these instances: More inclusive prohibitions, expanded prohibitions, and simultaneous prohibitions.

The Gemara continues to clarify the opinion of Rabbi Meir: And in accordance with whose opinion is the statement of Rabbi Meir? If you say that it is in accordance with the opinion of Rabbi Yehoshua, this is difficult. Didn’t Rabbi Yehoshua say that one who erred with regard to a mitzva is exempt from bringing a sin-offering, i.e., one who unwittingly performed a transgression while intending to perform a mitzva is exempt from punishment? In the case in the mishna as well, the men intended to perform the mitzva of marriage but unwittingly violated a transgression because the wives were switched. Therefore, according to the opinion of Rabbi Yehoshua, they should be exempt from a sin-offering. Rather, this must be in accordance with the opinion of Rabbi Eliezer, who holds that even if one mistakenly transgressed while attempting to perform a mitzva, he is still obligated to bring a sin-offering.

If you wish, resolve this differently and say: Actually, this can be explained even according to the opinion of Rabbi Yehoshua. When Rabbi Yehoshua says that one who erred with regard to a mitzva is exempt, this applies only to the case of babies who were mixed up in such a way that on Shabbat the mohel mistakenly circumcised a baby whose time had not yet come for circumcision. Since the mohel did not fulfill the mitzva of circumcision, he should be liable for performing prohibited labor on Shabbat. However, Rabbi Yehoshua exempts him from a sin-offering since he is pressed for time. Because circumcision must be performed only on the day specified, he was rushed and anxious to perform the circumcision, and due to this sense of urgency he erred and thought that the proper time was on Shabbat. In this case in the mishna, however, where the mistake involved marriage, since the brothers were not pressed for time Rabbi Yehoshua does not deem the brothers exempt.

The Gemara objects: And yet in the case of eating teruma, where one is not pressed for time and nevertheless Rabbi Yehoshua exempts him if the act involved a mitzva, as we learned in a mishna (Pesaḥim 72b): If a priest was partaking of teruma and it became known that he was the son of a divorced woman or the son of a ḥalutza and thereby disqualified from the priesthood and prohibited from eating teruma, Rabbi Eliezer deems him liable to pay the value of the principal and an additional fifth, like any non-priest who unwittingly ate teruma. However, Rabbi Yehoshua exempts him because at the time of consumption he intended to perform a mitzva, for he thought that he was a priest eating of the teruma.

The Gemara responds: But wasn’t it stated with regard to that mishna: Rav Beivai bar Abaye said: Here we are dealing with leavened teruma that was being eaten by the priest on the eve of Passover, for he is pressed for time. In this case, he would rush to eat it so that it would not have to be burned.

The Gemara offers a different attribution of the mishna: And if you wish, say a different explanation: The mishna is not according to the opinion of Rabbi Meir, who deems one liable in cases of more inclusive prohibitions and expanded prohibitions. Rather, the mishna is referring only to cases of simultaneous prohibitions, and in accordance with the opinion of Rabbi Shimon.

The Gemara asks: Granted, with regard to all of the prohibitions in the mishna, you can find that they take effect simultaneously in the case where the men appointed a single agent to betroth the women for them, and the women appointed an agent to accept the betrothals for them, and one agent encounters the other agent. In this scenario, all the men become betrothed to all the women the moment that the agents meet, and the prohibitions all take effect simultaneously. However, with regard to the prohibition pertaining to menstruating women, how can you find the case where both women become menstruating women at the exact time of betrothal?

Rav Amram said that Rav said: This is referring to a situation where the women continuously discharge menstrual blood from within the thirteenth year of the brothers until after they reached the age of thirteen, in order to deem the men liable for the prohibition pertaining to a menstruating woman. At the moment that the boys reached maturity and the betrothals went into effect, the sisters were forbidden as menstruating women. And the women were continuously discharging blood from within the twelfth year of the women until after the age of twelve, in order to deem the women liable for engaging in relations as a menstruating woman. Therefore, if this took place in such a way that on the exact day when the men reached maturity, i.e., their thirteenth birthday, the women reached maturity, i.e., their twelfth birthday, and at that moment they were menstruating, then all of the prohibitions would take effect simultaneously and they would be liable on all counts, according to Rabbi Shimon as well.

§ The mishna taught that we separate these women from their husbands for three months, as perhaps they became pregnant. The Gemara asks: But isn’t it known that a virgin woman does not become pregnant from her first sexual act? Rav Naḥman said that Rabba bar Avuh said: This is referring to a situation where they engaged in intercourse and then repeated the act, so that it is possible that the women were impregnated during the second act of intercourse. The Gemara asks: But if this is so, how can one explain that which Rabbi Ḥiyya teaches: Here, then, are sixteen sin-offerings? If there were indeed two acts of intercourse, then there should be thirty-two sin-offerings, since each prohibition was violated twice.

The Gemara answers: And according to your reasoning, that Rabbi Ḥiyya’s enumeration of sin-offerings applies to all acts of intercourse, then according to the opinion of Rabbi Eliezer, who deems one liable to bring a sin-offering for each and every thrusting movement during a single act of intercourse, there would be many prohibitions that were violated. This would greatly multiply the number of sin-offerings required. Rather, it must be that Rabbi Ḥiyya, with regard to Rabbi Eliezer’s opinion, is enumerating only the first thrusting movement in the intercourse. And so too, with regard to the Rabbis’ opinion, he is enumerating only the first act of intercourse. If there were two acts of intercourse, however, the number of sin-offerings would be doubled.

Rava said to Rav Naḥman: