And likewise, a non-kosher behema is included in the category of a non-kosher ḥayya, and a kosher behema is included in the category of a kosher ḥayya. Accordingly, although the verse here is referring to a behema, it is understood to be referring collectively to both a behema and a ḥayya, and teaches that the carcasses of both types impart impurity. And upon hearing this, ben Azzai said to me in these words: Woe [ḥaval] unto ben Azzai, who did not serve Rabbi Yishmael.

The Gemara analyzes Rabbi Yishmael’s statement: From where do we derive that according to the Torah, a ḥayya is included in the category of a behema? As it is written: “These are the behema that you may eat: An ox, a sheep, and a goat, a deer, and a gazelle, and a fallow deer, and a wild goat, and an oryx, and an aurochs, and a wild sheep” (Deuteronomy 14:4–5). Despite employing the term “behema,” the verse also lists the deer and the gazelle, which are undomesticated animals. How is this possible? From here it is evident that a ḥayya is included by the Torah in the category of a behema.

From where do we derive that according to the Torah, a behema is included in the category of a ḥayya? As it is written: “These are the ḥayya that you may eat, among all the behema that are on the earth. Whatever parts the hoof” (Leviticus 11:2–3). How is this possible, that the verse mentions a ḥayya and then refers to a behema? This indicates that a domesticated animal is included in the category of a ḥayya by the Torah.

The Gemara further clarifies: The principle that a kosher ḥayya is included by the Torah in the category of a kosher behema is relevant with regard to the distinguishing characteristics of kosher animals. The Torah states with regard to a domesticated animal that only a species that chews its cud and has cloven hooves is kosher. Nevertheless, this requirement is understood as a reference to both domesticated and undomesticated animals.

The principle that a non-kosher ḥayya is included by the Torah in the category of a non-kosher behema is relevant with regard to the prohibition against mating one species with another. The Torah states the prohibition with regard to a behema: “You shall not let your animal [behema] mate with a diverse kind” (Leviticus 19:19). Nevertheless, this is understood as referring to both a behema and a ḥayya.

The principle that a non-kosher behema is included by the Torah in the category of a non-kosher ḥayya is relevant with regard to that which Rabbi Yehuda HaNasi taught, as it is taught in a baraita: The verse delineates a case in which one is obligated to bring a sliding-scale offering as an atonement: “A person who touched anything impure, or the carcass of a non-kosher undomesticated animal [ḥayya], or the carcass of a non-kosher domesticated animal [behema], or the carcass of an impure creeping animal, and is guilty, it having being hidden from him that he is impure” (Leviticus 5:2). But the nature of the transgression for which the person requires atonement is not apparent from the verse.

Rabbi Yehuda HaNasi says: Since a domesticated animal is also referred to as a ḥayya, it would be sufficient if I would read, i.e., the verse would write, only the clause about a ḥayya, and I would have known that one who touches a carcass of any non-kosher animal is impure. Why, then, is an explicit clause about a behema stated? It serves as the basis for a verbal analogy.

It is stated here, with regard to one who is unaware that he touched an impure item: “Non-kosher behema,” and it is likewise stated below, with regard to one who was aware that he touched an impure item: “Non-kosher behema,” in the following verse: “And when any one shall touch any impure thing, whether it is the impurity of man, or a non-kosher behema, and then eats of the flesh of a peace offering to the Lord, that soul shall be cut off from its people” (Leviticus 7:21). Just as below, the verse is referring to the defiling of sacrificial foods, so too here, the reference is to the defiling of sacrificial foods, and therefore one must bring a sliding-scale offering as an atonement.

The Gemara clarifies the final statement: The principle that a kosher behema is included by the Torah in the category of a kosher ḥayya is relevant with regard to the formation of children. As we learned in a mishna (Nidda 21a): With regard to a woman who miscarries a fetus that appears to be in the form of a type of behema, ḥayya, or bird, whether it had the form of a non-kosher species or a kosher species, if the fetus is a male, then she observes the periods of impurity and purity required for giving birth to a male.

The mishna continues: And if the fetus is a female, then she observes the periods required for giving birth to a female. After giving birth to a male, a woman is impure for seven days, during which it is prohibited for her to engage in intercourse. During the next thirty-three days she may immerse in a ritual bath at any time, after which she is permitted to engage in intercourse even should she then experience a discharge of uterine blood. Nevertheless, during the entire forty-day period she may not enter the Temple or be in contact with consecrated foods. After giving birth to a girl, the length of each of these periods is doubled to fourteen days and sixty-six days, respectively (see Leviticus 12:2–5).

If the sex of the fetus is unknown, she observes the strictures of a woman who gave birth both to a male and to a female. Accordingly, it is prohibited for her to engage in intercourse for the fourteen days after birth, after which she immerses in a ritual bath. After that she is permitted to engage in intercourse despite any discharge of uterine blood until the fortieth day after birth, i.e., for thirty-three days following the seven days she would have been prohibited from engaging in intercourse if the fetus was male. The prohibition against entering the Temple, however, continues until eighty days have passed from the birth.

This is the statement of Rabbi Meir. The Gemara elsewhere (Nidda 22b) explains that Rabbi Meir derives his opinion from the fact that the term “formation” is used to describe both the formation of man: “Then the Lord God formed man” (Genesis 2:7), and the formation of animals and birds: “The Lord God formed every animal [ḥayya] of the field, and every bird of the air” (Genesis 2:19). Furthermore, he holds that the term “ḥayya” is referring to both domesticated and undomesticated animals, and concludes that a woman observes these periods of purity and impurity if the fetus has the form of any of these types of animals.

And the Rabbis say: Any fetus that is not of human form is not regarded as an offspring with regard to observance of these periods of purity and impurity, and she is permitted to engage in intercourse provided she does not experience a discharge of uterine blood.

§ The Gemara returns to explaining the opinion of the Rabbis, cited in the mishna, who hold that a dead fetus found inside its mother’s womb does not impart impurity, irrespective of whether it is of a kosher or a non-kosher animal. Rabbi Yosei HaGelili disagrees and holds that a dead fetus inside a non-kosher animal imparts impurity. He derives this from the verse: “A person who touched anything impure, or the carcass of a non-kosher ḥayya, or the carcass of a non-kosher behema, or the carcass of an impure creeping animal, and is guilty” (Leviticus 5:2), which is referring only to non-kosher animals. The Gemara asks: And according to the Rabbis, why do I need this verse?

The Gemara answers: The entire verse comes to teach that which Rabbi Yehuda HaNasi taught in the baraita cited earlier, that the verse obligates one to bring a sliding-scale offering only in cases where one partook of consecrated foods or entered the Temple while in a state of impurity of which one was unaware.

MISHNA: With regard to a woman whose fetus died in her womb and the midwife extended her hand into the womb and touched the fetus, the midwife is thereby rendered impure with the seven-day impurity imparted by a corpse, and the woman remains ritually pure until the offspring emerges from the womb.

GEMARA: Rabba says: Just as a ritually impure item that is encapsulated within a body does not impart impurity to an item that comes in contact with it, so too, a ritually pure item that is encapsulated within a body cannot be rendered impure if it comes in contact with an impure item. For example, if one swallowed a ring that was ritually pure and then entered a tent containing a corpse, the ring would not be rendered impure.

The Gemara asks: From where do we derive that an encapsulated impure item does not impart impurity? As it is written: “And one who eats of its carcass shall wash his clothes, and be impure until the evening” (Leviticus 11:40), i.e., he must immerse his body and garments in a ritual bath, and he then becomes pure at sunset. Are we not dealing even with a case where one ate from the carcass close to sunset and then immersed? And yet the Merciful One states that he is pure once the sun sets, despite the fact that his stomach still contains pieces of the carcass that have not yet been digested. If so, it is apparent that an encapsulated impure item does not impart impurity.

The Gemara challenges: But perhaps it is different there, as with regard to the prohibition against eating a carcass the Torah states: “You shall not eat any carcass; you may give it to the gentile resident who is in your cities” (Deuteronomy 14:21). The juxtaposition of the two parts of the verse teaches that the prohibition is limited to a carcass that is fit to be given to a gentile resident, i.e., it is fit for human consumption. Accordingly, perhaps the carcass that the person ate does not impart impurity, as it is no longer fit for a gentile resident, i.e., it is now unsuitable for human consumption.

The Gemara comments that the effectiveness of the proof depends on whether a carcass can impart impurity to a person despite its not being fit for human consumption: This proof works out well according to the opinion of Rabbi Yoḥanan, who says: A carcass imparts impurity to both this, a person, and that, food, even if it is unfit for human consumption, until it is no longer fit for consumption by a dog. According to this opinion the proof is understood well, as the carcass in the person’s stomach still has the ability to impart impurity to him because it is still fit for consumption by a dog. Therefore, it is apparent that the only reason it does not impart impurity is that it is encapsulated within his body.

But according to the opinion of bar Padda, who says a carcass has the severe form of ritual impurity, which can impart impurity to people only while it is still fit to be eaten by a gentile resident and it has the light form of ritual impurity even until the point that it is no longer fit for consumption by a dog, this proof is flawed. This is because it is possible the carcass in the person’s stomach does not render him impure simply because it is no longer fit for human consumption. Can one claim that the carcass cannot impart impurity because it is no longer fit for a gentile resident?

Granted that the carcass is not fit to be eaten by someone when it was eaten in his presence, as he is aware that it was swallowed and considers it disgusting to eat a swallowed item, but it is still sometimes fit for a person to eat when it was eaten not in his presence and he is unaware that it had been previously swallowed. This is possible where one consumed a small piece of food and did not chew it prior to swallowing. The Gemara concedes this point and therefore accepts the proof.

The Gemara asks: We found a source for the halakha that an encapsulated impure item does not impart impurity. From where do we derive that a pure item that is encapsulated within another body cannot be rendered impure if it comes in contact with an impure item?

The Gemara explains: It is derived through an a fortiori inference: If an earthenware vessel that is closed with a tightly sealed cover, which does not shield, i.e., prevent, the impure piece of a corpse contained within it from imparting impurity to other items in the same tent as it; the Gemara interrupts the explication of the inference and clarifies: As the Master said: The impure piece of a corpse that is in a tight space; e.g., it is buried in the ground and there is not a handbreadth of hollow space above it, beneath the dirt, breaks through the earth above it and ascends up to the heavens, imparting impurity in that path. The Gemara resumes the explication of the inference: Although the tightly sealed earthenware vessel does not shield the impure item, it does shield a pure item contained within it from being rendered impure (see Numbers 19:15).