Talmud - Niddah 27b נידה כ״ז ב׳

one grain of dirt in a certain place in the mixture. That grain of dirt is thereby nullified by the dust of the corpse, and consequently the measure of the dust increases.

Rather, Rabba said that this is the reason for the opinion of Rabbi Shimon: The halakha with regard to a corpse in its ultimate state of dust is like the halakha in its initial state of decomposition: Just as with regard to its initial state, if another matter is mixed with the decomposing corpse it serves as a nullification [gangilon] of the corpse’s impurity, as the dust of a decomposed corpse can impart impurity only if it is not mingled with the dust of any other substance, so too, in the corpse’s ultimate state of dust, if another matter is mixed with it, that serves as a nullification of the impurity of the dust.

The Gemara asks: What is the source for the halakha that the dust of a corpse imparts impurity only if it is not mingled with the dust of any other substance? The Gemara answers: As it is taught in a baraita: Which is a corpse that has the halakha of dust, i.e., whose dust imparts impurity; and which is a corpse that does not have the halakha of dust? If a corpse was buried naked in a marble coffin or on a stone floor, that is a corpse that has the halakha of dust that imparts impurity. Since any dust found there must have come from the corpse, it imparts impurity.

And what is a corpse that does not have the halakha of dust? If a corpse was buried in its cloak, or in a wooden coffin, or on a brick floor, that is a corpse that does not have the halakha of dust that imparts impurity, as it is assumed that some of the dust is from particles of the clothes, wood, or bricks, and the dust from a decomposed corpse imparts impurity only if it is not mingled with the dust of any other substance. The baraita adds another halakha with regard to the impurity of the dust of a corpse: And the Sages said that the dust of a corpse is impure only with regard to the corpse of a person who died naturally, excluding one who was killed, whose dust is not impure.

§ The Gemara returns to discuss the matter itself, i.e., the baraita cited above that clarifies the opinion of Rabbi Shimon: In the case of a ladleful of dust from a corpse into which any amount of dirt fell, the house is impure; and Rabbi Shimon deems it pure. The baraita continues: In the case of a ladleful of dust from a corpse that was scattered in the house, the house is impure. Provided that there is a sufficient amount of dust in the house, the house is impure, even if the dust is scattered. And Rabbi Shimon deems it pure.

The Gemara comments: And it is necessary for the baraita to state both of these halakhot. As, if the baraita had taught us only the first halakha, with regard to dust from a corpse in which dirt was mixed, one might have thought that it is specifically in that case that the Rabbis say the house is impure, because the dust is concentrated in one place; but if the dust was scattered, one might say that the Rabbis concede to Rabbi Shimon that the house is pure. The reasoning is that if an item overlies a collection of dust of a corpse that is insufficient to render it impure and also overlies another collection of similar size, where together these collections constitute a sufficient amount to render the item and everything under it impure, it is not impure.

And if the baraita had taught us the halakha only with regard to this second case, where the dust of the corpse was scattered, one might have thought that it is specifically in this case that Rabbi Shimon says that the house is pure, as an item that overlies an insufficient collection of the dust of a corpse and also overlies another collection, where together these collections constitute a sufficient amount to render the item impure, is not impure. But in that first case, where dirt was mixed with the dust of the corpse, one might say that Rabbi Shimon concedes to the Rabbis that the house is impure. Therefore, it is necessary for the baraita to teach both cases.

There is a different dispute between Rabbi Shimon and the Rabbis that is taught in another mishna (Oholot 2:2): If a house contains a ladleful of dirt from a cemetery and slightly more, the house is impure; and Rabbi Shimon deems it pure. The Gemara asks: What is the reason for the opinion of the Rabbis? The Gemara answers: They deem the house impure as it is impossible for slightly more than a ladleful of dirt from a cemetery not to contain a ladleful of dust from a corpse.

§ The Gemara asks: Now that you say that the reason that Rabbi Shimon deems the house pure, in a case where it contains dust from a corpse in which dirt was mixed, is that in his opinion the halakha of a corpse in its ultimate state of dust is like the halakha in its initial state of decomposition, then with regard to a case where there is an afterbirth in the house, what is the reason that Rabbi Shimon deems the house pure? Rabbi Yoḥanan says: The Sages touched upon it, i.e., deemed the house pure, due to the nullification of the disintegrated offspring by the majority of the blood that emerged during the miscarriage, in which the afterbirth was mixed.

And Rabbi Yoḥanan follows his line of reasoning in this regard, as Rabbi Yoḥanan says: Rabbi Shimon and Rabbi Eliezer ben Ya’akov both said the same thing, i.e., they both issued rulings based on the same principle. The relevant statement of Rabbi Shimon is that which we said, i.e., that if a woman discharged an afterbirth the house is pure, as the offspring is nullified by the blood that emerged during the miscarriage. Rabbi Eliezer ben Ya’akov said that which is taught in a mishna (Bekhorot 21a): Rabbi Eliezer ben Ya’akov says: In the case of a large animal that expelled a mass of congealed blood, that mass must be buried, as perhaps there was a male fetus there, which was consecrated as a firstborn when it emerged, and the animal is exempt from having any future offspring being counted a firstborn.

And Rabbi Ḥiyya teaches a baraita with regard to that halakha: The mass of congealed blood does not impart ritual impurity, neither through physical contact nor through carrying it. It does not have the status of an unslaughtered animal carcass, which does impart impurity in such manners. The Gemara asks: But since the mass does not impart impurity, neither through contact nor through carrying, which indicates that it is not considered a fetus, why must it be buried? The Gemara answers: It must be buried in order to publicize that the animal is exempt from having its future offspring being counted a firstborn.

The Gemara asks: If the animal’s subsequent offspring is not counted a firstborn, evidently the mass is treated like a full-fledged offspring. But if so, why does Rabbi Ḥiyya teach that it does not impart impurity, neither through physical contact nor through carrying? Rabbi Yoḥanan says: It is due to the halakhic nullification of a foreign substance in a majority of permitted substances that the Sages touched upon it, to exclude it from impurity through contact or carrying. In other words, the fetus is considered a full-fledged offspring, but it does not impart impurity, because it is nullified by the rest of the congealed mass.

§ The Gemara resumes its discussion of the opinion of Rabbi Shimon that if a woman discharges an afterbirth in a house, the house is pure. Rabbi Ami says that Rabbi Yoḥanan says: And Rabbi Shimon concedes that its mother is impure with the impurity of a woman after childbirth.

A certain elder said to Rabbi Ami: I will explain to you the reason for the statement of Rabbi Yoḥanan. As the verse states: “If a woman bears seed and gives birth to a male, she shall be impure seven days, as in the days of the menstruation of her sickness she shall be impure” (Leviticus 12:2). This indicates that even if a woman gives birth to an offspring that is similar only to the seed that she bore, i.e., if the offspring liquefied and became similar to semen, the woman is impure with the impurity of a woman after childbirth.

§ Reish Lakish says: In the case of a fetus in a gestational sac, that was mashed in its amniotic fluid by being shaken violently, it is rendered like a corpse that was deformed, and therefore it does not impart impurity to other items that are under the same roof.

Rabbi Yoḥanan said to Reish Lakish: From where do we derive that a corpse that was deformed is pure? If we say it is derived from that which Rabbi Shabbtai says that Rabbi Yitzḥak from Migdal [Migdala’a] says, and some say from that which Rabbi Yitzḥak from Migdal says that Rabbi Shabbtai says, that cannot be correct. The Gemara cites the relevant statement: With regard to a corpse that was burned but its form [veshildo] still exists, i.e., it still has the form of a human corpse, it is impure. There was an incident involving such a corpse, and the Sages deemed impure all items that were under the large openings of the house where the corpse was located, as these openings were fit for the removal of the corpse from the house through them.

Traduction : The William Davidson digital edition of the Koren Noé Talmud, with commentary by Rabbi Adin Even-Israel Steinsaltz.

Nidah 27b examines how mixing foreign matter with a decomposed corpse's dust nullifies its capacity to transmit ritual impurity under Rabbi Shimon's view.