Niddah 25

פרשתבינא דפומבדיתא קאי ליה לאדא דיילא עד פלגיה וכולי עלמא קאי לפרשתבינא דפומבדיתא עד חרציה

and when the governor [parashtevina] of Pumbedita would stand next to Adda the attendant, he would reach only half of his height. And when everyone else in the world would stand next to the governor of Pumbedita, they would reach only his loins [ḥartzeih].

שאלו לפני רבי המפלת שפיר מלא בשר מהו אמר להם לא שמעתי

§ The students asked Rabbi Yehuda HaNasi: In the case of a woman who discharges a gestational sac full of flesh, what is the halakha? Does she have the impurity of a woman after childbirth? Rabbi Yehuda HaNasi said to them: I have not heard from my teachers the halakha in this case.

אמר לפניו רבי ישמעאל ברבי יוסי כך אמר אבא מלא דם טמאה נדה מלא בשר טמאה לידה

Rabbi Yishmael, son of Rabbi Yosei, said to him: This is what my father, i.e., Rabbi Yosei ben Ḥalafta, one of Rabbi Yehuda HaNasi’s teachers, said: If a woman discharged a gestational sac full of blood, she is impure with the impurity of a menstruating woman. If it is full of flesh, she is impure with the impurity of a woman after childbirth.

אמר ליה אילמלי דבר חדש אמרת לנו משום אביך שמענוך עכשיו

Rabbi Yehuda HaNasi said to him: If you had told us an entirely new statement in the name of your father, no part of which was also stated by another Sage, we would have listened to you, i.e., we would have accepted the statement as halakha. But now that you stated two halakhot, one with regard to a woman who discharged a gestational sac full of blood, and the other with regard to a woman who discharged a gestational sac full of flesh, the entire statement cannot be accepted as halakha.

מדהא קמייתא כיחידאה קאמר כסומכוס שאמר משום רבי מאיר הא נמי שמא כרבי יהושע אמרה ואין הלכה כרבי יהושע

Rabbi Yehuda HaNasi explains: From the fact that Rabbi Yosei said this first clause of his statement, with regard to a gestational sac full of blood, in accordance with an individual opinion, i.e., in accordance with the opinion of Sumakhos, who said in the name of Rabbi Meir that the woman is impure, contrary to the opinion of the other Sages, it follows that with regard to this latter statement as well, with regard to a gestational sac full of flesh, one can say that perhaps Rabbi Yosei said it in accordance with the opinion of another individual Sage, Rabbi Yehoshua. And the halakha is not in accordance with the opinion of Rabbi Yehoshua.

דתניא המפלת שפיר שאינו מרוקם רבי יהושע אומר ולד וחכמים אומרים אינו ולד

As it is taught in a baraita: In the case of a woman who discharges a gestational sac in which tissue did not develop, Rabbi Yehoshua says: It has the status of an offspring, and the woman has the impurity of a woman after childbirth; and the Rabbis say: It is not an offspring, and the woman is pure. The opinion of Rabbi Yosei that a woman who discharged a gestational sac full of flesh is impure might be in accordance with the ruling of Rabbi Yehoshua, which is not accepted as halakha, since the majority of the other Sages disagree with him. Therefore, the halakha cannot be decided in accordance with either part of the statement of Rabbi Yosei.

אמר רבי שמעון בן לקיש משום רבי אושעיא מחלוקת בעכור אבל בצלול דברי הכל אינו ולד ורבי יהושע בן לוי אמר בצלול מחלוקת

Rabbi Shimon ben Lakish says in the name of Rabbi Oshaya: The dispute between Rabbi Yehoshua and the Rabbis applies in a case where the amniotic fluid is turbid, as Rabbi Yehoshua holds that the turbidity indicates that there was likely an embryo in the sac that liquefied. But in a case where the amniotic fluid is clear, everyone agrees that the discharged sac is not considered an offspring. And Rabbi Yehoshua ben Levi says: The dispute applies in a case where the amniotic fluid is clear.

איבעיא להו בצלול מחלוקת אבל בעכור דברי הכל ולד או דלמא בין בזה ובין בזה מחלוקת תיקו

A dilemma was raised before the Sages: What does Rabbi Yehoshua ben Levi mean? Does he mean that the dispute applies only in a case where the amniotic fluid is clear, but in a case where it is turbid, everyone agrees that it has the halakhic status of an offspring? Or perhaps Rabbi Yehoshua ben Levi means that the dispute applies in this case and in that case, i.e., the Rabbis hold that the sac does not have the status of an offspring even if the amniotic fluid is turbid. The Gemara concludes that the dilemma shall stand unresolved.

מיתיבי את זו דרש רבי יהושע בן חנניא ויעש ה׳ אלהים לאדם ולאשתו כתנות עור וילבשם מלמד שאין הקדוש ברוך הוא עושה עור לאדם אלא אם כן נוצר

The Gemara raises an objection to the opinion that the dispute between Rabbi Yehoshua and the Rabbis applies only in a case where the amniotic fluid is turbid. It is taught in a baraita that Rabbi Yehoshua ben Ḥananya, who is the same Rabbi Yehoshua who disagrees with the Rabbis with regard to the case of a woman who discharges a gestational sac in which tissue did not develop, taught this following proof for his opinion that the woman is impure: It is stated: “And the Lord God made for Adam and for his wife garments of skins, and clothed them” (Genesis 3:21). This teaches that the Holy One, Blessed be He, does not make skin for a person unless he is already created, as God first created Adam and Eve, and then gave them skin. Consequently, the existence of a gestational sac proves that there is an offspring.

אלמא בעור תליא מילתא לא שנא עכור ולא שנא צלול

Evidently, according to Rabbi Yehoshua the matter of whether or not an embryo is considered offspring is dependent on whether or not there is skin, and there is no difference whether the amniotic fluid is turbid, and there is no difference whether it is clear.

אי אמרת בשלמא בצלול מחלוקת היינו דאיצטריך קרא אלא אי אמרת בעכור מחלוקת למה לי קרא סברא בעלמא הוא אלא שמע מינה בצלול מחלוקת שמע מינה

Granted, if you say that the dispute applies in a case where it is clear, that is why it was necessary for Rabbi Yehoshua to derive from a verse that an embryo that has skin is considered an offspring. But if you say that the dispute applies in a case where the amniotic fluid is turbid, but Rabbi Yehoshua concedes that the woman is pure if it is clear, why do I need a verse to teach that if the amniotic fluid is turbid the woman is impure? It is logical that where the amniotic fluid is turbid there was probably an embryo that liquefied. Rather, conclude from it that the dispute applies in a case where the amniotic fluid is clear. The Gemara concludes: Conclude from it that this is correct.

וכן אמר רב נחמן אמר רבה בר אבוה מחלוקת בעכור אבל בצלול דברי הכל אינו ולד

And likewise, just as Rabbi Oshaya interprets the dispute between Rabbi Yehoshua and the Rabbis as referring to a case where the amniotic fluid is turbid, Rav Naḥman says that Rabba bar Avuh says: The dispute between Rabbi Yehoshua and the Rabbis applies in a case where the amniotic fluid is turbid; but in a case where the amniotic fluid is clear, everyone agrees that the discharged sac is not considered an offspring.

איתיביה רבא לרב נחמן אלא אמרו סימן ולד בבהמה דקה טינוף בגסה שליא באשה שפיר ושליא

Rava raised an objection to the opinion of Rav Naḥman from a mishna that specifies the obligations that apply to firstborn animals (Bekhorot 19b):But the Sages said that not only does a viable offspring exempt any subsequent offspring from being counted a firstborn, but the same applies to an indication of the offspring that is discharged from the womb. The indication in a small animal is a murky discharge from the womb, in a large animal it is the emergence of an afterbirth, and in a woman the indication is a gestational sac or an afterbirth.

ואילו שפיר בבהמה לא פטר אי אמרת בשלמא בצלול מחלוקת משום הכי

Rava infers: And yet the miscarriage of a gestational sac in the case of a large animal does not exempt the animal’s subsequent offspring from being counted a firstborn. Granted, if you say that the dispute between Rabbi Yehoshua and the Rabbis applies in a case where the amniotic fluid is clear, it is due to that reason that the mishna differentiates between a large animal and a woman with regard to a gestational sac.

אשה דרבי בה קרא פטר בה שפיר בבהמה דלא רבי קרא לא פטר בה שפיר

Rava explains: With regard to a woman, as the aforementioned verse: “And the Lord God made for Adam and for his wife garments of skins,” includes in the definition of offspring a gestational sac, i.e., skin, one can say that such a gestational sac exempts subsequent births from the obligations of primogeniture. By contrast, in the case of an animal, as the verse does not include a gestational sac in the definition of offspring, discharging a gestational sac does not exempt the animal’s subsequent offspring from being considered a firstborn.

אלא אי אמרת בעכור מחלוקת מכדי סברא הוא מאי שנא אשה ומאי שנא בהמה

But if you say that the dispute applies in a case where the amniotic fluid is turbid, and Rabbi Yehoshua deems the woman impure due to the likelihood that there was an embryo that liquefied, since this halakha is based on logic, what is different in the case of a woman, and what is different in the case of an animal? Rabbi Yehoshua’s reasoning applies equally to both. Evidently, the dispute applies in a case where the amniotic fluid is clear.

מי סברת רבי יהושע מפשט פשיט ליה רבי יהושע ספוקי מספקא ליה ואזיל הכא לחומרא והכא לחומרא

The Gemara answers: Do you hold that it is obvious to Rabbi Yehoshua that a gestational sac in which the amniotic fluid is turbid has the halakhic status of an offspring? That is not so; rather, Rabbi Yehoshua is uncertain of its halakhic status, and therefore here, in this case, he rules stringently, and there he also rules stringently.

גבי אשה דממונא הוא ספק ממונא לקולא

The Gemara elaborates: First of all, with regard to a situation where a woman discharged a gestational sac in which the amniotic fluid was turbid, in which case the obligation of primogeniture is a monetary matter, i.e., the obligation to redeem the newborn child by paying money to a priest, the subsequent births are exempt, in accordance with the principle that uncertainty with regard to monetary matters is treated leniently.

גבי בהמה דאיסורא הוא דאיכא לגבי גיזה ועבודה ספק איסורא לחומרא הכי נמי גבי אשה ספק טומאה לחומרא

By contrast, with regard to an animal, in which case firstborn status is a ritual matter, as there are prohibitions involving, i.e., against, shearing the animal’s wool and using the animal for labor before it incurs a blemish, the discharged gestational sac is not considered an offspring and does not exempt subsequent births from the obligations of firstborn status, as uncertainty with regard to ritual matters is treated stringently. So too, with regard to the impurity of a woman who discharged a gestational sac, she is deemed impure, as uncertainty with regard to impurity is treated stringently, which means that for the purposes of this halakha a gestational sac is considered an offspring.

ומי מספקא ליה והא קרא קאמר מדרבנן וקרא אסמכתא בעלמא הוא

The Gemara asks: And is Rabbi Yehoshua uncertain about the halakha of a woman who discharges a gestational sac? But doesn’t he cite a verse as proof that the woman has the impurity of one who gave birth? The Gemara answers: Rabbi Yehoshua maintains that the woman is impure by rabbinic law, and the verse he cites is a mere support for this halakha; it is not the actual source.

אמר ליה רב חנינא בר שלמיא לרב הא רבי הא רבי ישמעאל ברבי יוסי והא רבי אושעיא והא רבי יהושע בן לוי מר כמאן סבירא ליה

Rav Ḥanina bar Shelamya said to Rav: This is the opinion of Rabbi Yehuda HaNasi, who told his students that he did not hear from his teachers the halakha in the case of a woman who discharged a gestational sac full of flesh; and this is the opinion of Rabbi Yishmael, son of Rabbi Yosei, who cited his father’s opinion that in such a case the woman is impure. And this is the opinion of Rabbi Oshaya, that the dispute between Rabbi Yehoshua and the Rabbis applies only in a case where the amniotic fluid is turbid; and finally this is the opinion of Rabbi Yehoshua ben Levi, who holds that the dispute applies if the amniotic fluid is clear. In accordance with whose opinion does the Master hold?

אמר ליה אני אומר אחד זה ואחד זה אינה חוששת

Rav said to Rav Ḥanina bar Shelamya: I say that both in this case, where the amniotic fluid is turbid, and in that case, where the fluid is clear, the woman does not need to be concerned that she has the status of a woman who gave birth to an offspring.

ושמואל אמר אחד זה ואחד זה חוששת ואזדא שמואל לטעמיה דכי אתא רב דימי אמר מעולם לא דכו שפיר בנהרדעא לבר מההוא שפירא דאתא לקמיה דשמואל דמנח עליה חוט השערה מהאי גיסא וחזיא מהאי גיסא אמר אם איתא דולד הואי לא הוה זיג כולי האי

And Shmuel says: In both this case and that case, the woman must be concerned that the discharged gestational sac has the status of an offspring, and therefore she is considered impure like a woman who gave birth. And Shmuel follows his standard line of reasoning here, as when Rav Dimi came and transmitted many halakhic traditions, the latter said: In Neharde’a the Sages never deemed a woman who discharged a gestational sac pure, except for the case of a certain gestational sac that came before Shmuel, who placed a hair on this side of that sac, and it was visible from that side. Shmuel said, based on this test: If it were so, that there was an offspring in the sac, it would not have been so transparent. He therefore deemed the woman pure, but his ruling applied only in that extreme case.

ואם היה מרוקם וכו׳ תנו רבנן איזהו שפיר מרוקם אבא שאול אומר תחלת ברייתו מראשו ושתי עיניו כשתי טיפין של זבוב תני רבי חייא מרוחקין זה מזה שני חוטמין כשתי טיפים של זבוב

§ The mishna teaches: But if the sac was one in which tissue developed, the halakhic status of the woman is that of a woman after childbirth. Since the sex of the embryo is unknown, she observes the strictures of a woman who gave birth both to a male and to a female; she is impure for fourteen days like a woman who gave birth to a female, but blood that she sees thereafter is pure only until forty days after birth, like a woman who gave birth to a male. The Sages taught in a baraita: What is the definition of a gestational sac in which tissue developed? Abba Shaul says: The beginning of the formation of the embryo is from its head, and its two eyes look like two drops, similar to the eyes of a fly. Rabbi Ḥiyya teaches: These eyes must be distant from each other. Furthermore, its two nostrils look like two drops, similar to the nostrils of a fly.

תני רבי חייא ומקורבין זה לזה ופיו מתוח כחוט השערה וגויתו כעדשה ואם היתה נקבה נדונה כשעורה לארכה

Rabbi Ḥiyya teaches: And these eyes must be close to each other. And its mouth stretches along the width of its face like a strand of hair. And its body is like the size of a lentil. And if it was female, its vagina can be discerned by the appearance of a line like a cracked grain of barley oriented along the length of its body.

וחתוך ידים ורגלים אין לו ועליו מפורש בקבלה הלא כחלב תתיכני וכגבינה תקפיאני עור ובשר תלבישני ועצמות וגידים תסוככני חיים וחסד עשית עמדי ופקדתך שמרה רוחי

And it does not have the shape of arms and legs at this stage. And it is said with regard to an embryo at this stage, in the texts of tradition, the Prophets: “Have You not poured me out as milk, and curdled me like cheese? You have clothed me with skin and flesh, and knit me together with bones and sinews. You have granted me life and favor, and Your providence has preserved my spirit” (Job 10:10–12).

ואין בודקין אותו במים שהמים עזין

And one does not examine it with water to discover its sex, as water is too strong,

וטורדין אותו אלא בודקין אותו בשמן שהשמן רך ומצחצחו ואין רואין אלא בחמה

and dissolves it. Rather, one examines it with oil, as oil is soft and cleans the embryo so that its sex can be discerned. And one views it only in the light of the sun.

כיצד בודקין אותו כיצד בודקין אותו כדאמרינן אלא במה בודקין אותו לידע אם זכר הוא אם נקבה היא

The baraita continues: How does one examine the embryo? The Gemara expresses surprise at this question: How does one examine it to determine whether it has the halakhic status of an offspring? Clearly, one examines it as we just said. Rather, the question is as follows: In what manner does one examine it to ascertain whether it is male or whether it is female?

אבא שאול בר נש ואמרי לה אבא שאול בר רמש אומר מביא קיסם שראשו חלק ומנענע באותו מקום אם מסכסך בידוע שזכר הוא ואם לאו בידוע שנקבה היא

Abba Shaul bar Nash, and some say Abba Shaul bar Remash, says: One brings a sliver of wood whose top is smooth, and he moves it along the embryo in that place, i.e., the sex organ. If the sliver is caught, i.e., its movement is not smooth, it is known that the embryo is male, as its member interfered with the movement of the sliver. And if the sliver is not caught, it is known that it is female.

אמר רב נחמן אמר רבה בר אבוה לא שנו אלא מלמטה למעלה אבל מן הצדדין אימא כותלי בית הרחם נינהו

Rav Naḥman says that Rabba bar Avuh says: They taught this halakha, that if the movement of the sliver is not smooth then the embryo is male, only if the sliver was moved along the sex organ of the embryo from below to above; but if it was moved from the sides, from one side to the other, the fact that it was not smooth does not prove that the embryo is male, as one can say that the sides of the womb interfered.

אמר רב אדא בר אהבה תנא אם היתה נקבה נדונה כשעורה סדוקה מתקיף לה רב נחמן ודילמא חוט של ביצים נינהו אמר אביי השתא ביצים גופייהו לא ידיעי חוט של ביצים ידיע

Rav Adda bar Ahava says: The complete version of the baraita is taught as follows: If it was female, its vagina can be discerned by the appearance of a line like a cracked grain of barley oriented along the length of its body. Rav Naḥman objects to this: But perhaps it is not the vagina but the recess between the testes, and the embryo is male. Abaye said to him: Now, at this stage of development, the testes of the embryo themselves are not discernible. Is it possible that the recess between the testes is discernible?

אמר רבי עמרם תנא שתי ירכותיו כשני חוטין של זהורית ואמר רבי עמרם עלה כשל ערב ושני זרועותיו כשני חוטין של זהורית ואמר רבי עמרם עלה כשל שתי

The baraita teaches that at this stage an embryo does not have the shape of arms and legs. Rabbi Amram says that it is taught in a baraita that when an embryo’s arms and legs start to take shape, its two thighs look like two strings of crimson thread [zehorit]. And Rabbi Amram says with regard to this matter that the thighs look like two strings of the woof, which are thicker than those of the warp. The baraita adds: And its two arms look like two strings of crimson thread. And Rabbi Amram says with regard to this matter that the arms look like two strings of the warp.

אמר ליה שמואל לרב יהודה שיננא לא תעביד עובדא עד שישעיר ומי אמר שמואל הכי והאמר שמואל אחת זו ואחת זו חוששת

Shmuel said to Rav Yehuda: Shinnana, do not perform an action, i.e., do not issue a practical ruling deeming a woman who discharges an embryo at this stage of development impure, unless the embryo has grown hair. The Gemara asks: And did Shmuel actually say that? But doesn’t Shmuel say with regard to a woman who discharged a gestational sac that both in this case, where the amniotic fluid is turbid, and in that case, where the fluid is clear, the woman must be concerned that the discharged gestational sac might have the status of an offspring, which would mean that she is impure even without the growth of hair on the embryo?

אמר רב אמי בר שמואל לדידי מפרשא לי מיניה דמר שמואל לחוש חוששת ימי טהרה לא יהבינן לה עד שישעיר

Rav Ami bar Shmuel says: This matter was explained to me by Mar Shmuel: As for being concerned that perhaps she is impure, the woman must be concerned, due to the uncertainty whether she discharged an offspring. But we do not give her the days of purity that follow the period of impurity for a woman who gave birth, unless the embryo has grown hair.

למימרא דמספקא ליה לשמואל והא ההוא שפירא דאתאי לקמיה דמר שמואל אמר הא בר ארבעין וחד יומא וחשיב מיומא דאזלא לטבילה עד ההוא יומא ולא הוה אלא ארבעין יומין

The Gemara asks: Is that to say that Shmuel is uncertain whether a gestational sac has the halakhic status of an offspring? But there was an incident involving a certain gestational sac that was brought before Mar Shmuel, and Shmuel said: This embryo is forty-one days old. And Shmuel subsequently calculated the amount of time that had passed from the day that the woman went to perform immersion in a ritual bath until that day, and it was only forty days.

ואמר להו האי בנדה בעל כפתיה ואודי שאני שמואל דרב גובריה

And he said to the local court: This husband engaged in intercourse with his wife when she was a menstruating woman. They bound the husband and he confessed. Since Shmuel was so proficient in embryology, why was he unsure about the halakhic status of a gestational sac? The Gemara answers: Shmuel himself is different, as his strength, i.e., his proficiency, was great. His general ruling that the halakhic status of a gestational sac is uncertain applies to people who are not as proficient as he is.

המפלת סנדל וכו׳ תנו רבנן סנדל דומה לדג של ים מתחלתו ולד הוא אלא שנרצף רבן שמעון בן גמליאל אומר סנדל דומה ללשון של שור הגדול משום רבותינו העידו סנדל צריך צורת פנים

§ The mishna teaches that a woman who discharges a sandal fetus or one who discharges an afterbirth observes the strictures of a woman who gave birth both to a male and to a female. The Sages taught in a baraita: A sandal fetus has a similar appearance to a certain fish of the sea known as a sandal fish;it looks as though it is a full-fledged offspring from the outset, but it was mashed. Rabban Shimon ben Gamliel says: A sandal fetus has an appearance that is similar to the tongue of the large bull. Students testified in the name of our teachers that for a sandal fetus to have the halakhic status of an offspring, it requires the shape of a face.

אמר רב יהודה אמר שמואל הלכה סנדל צריך צורת פנים אמר רב אדא אמר רב יוסף אמר רבי יצחק סנדל צריך צורת פנים ואפילו מאחוריו משל לאדם שסטר את חבירו והחזיר פניו לאחוריו

Rav Yehuda says that Shmuel says: The halakha is that a sandal fetus requires the shape of a face for it to have the status of an offspring. Rav Adda says that Rav Yosef says that Rabbi Yitzḥak says: A sandal fetus requires the shape of a face, but the face does not need to be in its proper location; even if the face is on the back of its head, the fetus has the status of an offspring. A parable to which this situation can be compared is that of a person who slapped another in the face and pushed his face back. Here too, the face of the sandal fetus was pushed back due to external pressure.

בימי רבי ינאי בקשו לטהר את הסנדל שאין לו צורת פנים אמר להם רבי ינאי טיהרתם את הוולדות

The Gemara relates: In the days of Rabbi Yannai, the other Sages wished to deem pure a woman who discharges a sandal fetus that does not have the shape of a face. Rabbi Yannai said to them: You have deemed pure women who discharge offspring. Rabbi Yannai holds that even a sandal fetus that does not have the shape of a face is considered an offspring.

והתניא משום רבותינו העידו סנדל צריך צורת פנים אמר רב ביבי בר אביי אמר רבי יוחנן מעדותו של רבי נחוניא נשנית משנה זו אמר רבי זעירא זכה בה רב ביבי בשמעתיה דאנא והוא הוינא יתבינן קמיה דרבי יוחנן כי אמרה להא שמעתא וקדם איהו ואמר וזכה בה

The Gemara asks: But isn’t it taught in a baraita that students testified in the name of our teachers that for a sandal fetus to have the halakhic status of an offspring it requires the shape of a face? Rav Beivai bar Abaye says that Rabbi Yoḥanan says in response: This mishna, i.e., the ruling to which the students testified, is taught from the testimony of Rabbi Neḥunya. In other words, this ruling is the opinion of an individual tanna, which is not accepted. Rabbi Zeira says: Rav Beivai merited that his ruling of halakha, which he transmitted in the name of Rabbi Yoḥanan, was accepted. As he and I were both sitting before Rabbi Yoḥanan when Rabbi Yoḥanan said this halakha, but Rav Beivai said it first to the other Sages, and thereby merited that it was ascribed to him.

למה הזכירו סנדל והלא אין סנדל שאין עמו ולד

§ The Gemara asks: Why does the mishna mention that if a woman discharged a sandal fetus she observes the strictures of a woman who gave birth both to a male and to a female? Since there is no such thing as a sandal fetus that does not have another offspring with it, which mashed it and gave it the form of a sandal fish, in any case the woman has the impurity of a woman after childbirth.

אי דאתילידא נקבה בהדיה הכי נמי הכא במאי עסקינן דאתיליד זכר בהדיה

The Gemara answers: If it is a female offspring that is born with the sandal fetus, it is indeed unnecessary to mention the halakha of the sandal fetus, as the woman is in any case impure for two weeks. But here we are dealing with a case where a male is born with it, on account of which the woman would be impure for only seven days were it not for the sandal fetus.

מהו דתימא הואיל ואמר רב יצחק בר אמי אשה מזרעת תחילה יולדת זכר איש מזריע תחלה יולדת נקבה מדהא זכר הא נמי זכר

In this case, it is necessary for the mishna to state that the woman observes the strictures of one who gave birth both to a male and to a female, lest you say that since Rav Yitzḥak bar Ami says that the sex of a fetus is determined at the moment of conception, as, if the woman emits seed first she gives birth to a male and if the man emits seed first she gives birth to a female, therefore, it can be concluded from the fact that this offspring that was born with the sandal fetus is male, that this sandal fetus is also male.

קא משמע לן אימא שניהם הזריעו בבת אחת האי זכר והאי נקבה

Lest this reasoning be accepted, the mishna teaches us that the woman must observe the strictures of a woman who gave birth to a female as well. This is because one can say that perhaps both the man and the woman emitted seed at the same time, and consequently this offspring is male and that sandal fetus is female.

דבר אחר שאם תלד נקבה לפני שקיעת החמה וסנדל לאחר שקיעת החמה

Alternatively, it can be suggested that it is necessary for the mishna to state this halakha even with regard to a case where the twin of the sandal fetus is female, as, if the woman gives birth to the female before sunset and gives birth to the sandal fetus after sunset, which is considered the next day, the sex of the sandal fetus affects the count of the woman’s periods of impurity and purity.

מונה תחלת נדה לראשון ותחלת נדה לאחרון

If the sandal fetus is male, the woman’s status as a woman after childbirth ends after the eightieth day from the birth of the female offspring, and she counts the beginning of the period when seeing blood renders her impure as a menstruating woman from the birth of the first offspring, i.e., the female. But if the sandal fetus is female, the woman has the status of a woman after childbirth until after the eightieth day from its birth, which is the eighty-first day from the birth of the first offspring. If so, she counts the beginning of the period when seeing blood renders her impure as a menstruating woman from the birth of the last offspring, i.e., the sandal fetus.

סנדל דתנן

The Gemara discusses why the case of a woman who discharged a sandal fetus is mentioned in other mishnayot, given that a sandal fetus always has a twin. First the Gemara discusses the halakha of a woman who discharged a sandal fetus that we learned in a mishna