and the thigh bone of a sacrificial animal that was rendered unfit as piggul, i.e., an offering that was sacrificed with the intent to consume it after its designated time, or notar, i.e., part of an offering left over after the time allotted for its consumption, whether these thigh bones were sealed and there was no access to the marrow, or whether they were perforated and there was access to the marrow, one who touches them is ritually impure. The reason is that a piece of bone of a corpse the size of a barley grain imparts impurity, and the bone of a sacrificial animal that was disqualified in this manner imparts impurity by rabbinic decree via contact.

With regard to the thigh bone of an unslaughtered carcass and the thigh bone of a creeping animal, one who touches them when they are sealed remains ritually pure. If one of these thigh bones was perforated at all, it imparts impurity via contact, as in that case contact with the bone is tantamount to contact with the marrow. From where is it derived that even with regard to impurity transmitted via carrying there is a distinction between sealed and perforated thigh bones? It is derived from a verse, as the verse states: “One who touches the carcass thereof shall be impure until the evening; and one who carries the carcass thereof shall be impure until the evening” (Leviticus 11:39–40), indicating: That which enters the category of impurity via contact, enters the category of impurity via carrying; that which does not enter the category of impurity via contact, does not enter the category of impurity via carrying.

GEMARA: The mishna teaches that one who touches the thigh bone of a human corpse is ritually impure, whether or not it was sealed. The Gemara infers that with regard to one who touches the bone, yes, he is impure, but one who overlies the thigh bone is not impure, as it does not transmit impurity to that which is above it or under the same roof.

The Gemara asks: What are the circumstances? If there is an olive-bulk of flesh attached to the bone then it should transmit impurity in a tent, i.e., to that which is under the same roof, as well. The Gemara answers: The mishna is discussing a case where there is not an olive-bulk of flesh attached to the bone.

The Gemara objects: But if there is an olive-bulk of marrow inside the bone, the impurity breaks through the bone, so to speak, and ascends beyond it. Therefore, it should transmit impurity in a tent as well. The Gemara explains: The mishna is discussing a case where there is not an olive-bulk of marrow inside the bone.

The Gemara objects: But if the mishna maintains that marrow inside the bone of a living person heals the flesh outside the bone, then since the marrow could replenish itself and catalyze the growth of flesh on the bone it is a proper limb. Therefore, as is the case with any piece of a proper limb, even one less than the size of an olive-bulk, it should transmit impurity in a tent as well. Rav Yehuda, son of Rabbi Ḥiyya, says: That is to say that the mishna maintains that marrow inside the bone does not heal the flesh outside the bone.

The Gemara asks: To what case did you interpret the mishna to be referring? It is a case where there is not an olive-bulk of marrow. If so, in the case of a sacrificial animal, why does the thigh bone impart impurity? The Sages issued a decree that the bones of a sacrificial animal that are attached to flesh or contain marrow that became piggul or notar render those who touch them impure, as they serve as handles or protection for the flesh or marrow. By contrast, in this case there can be no piggul or notar because there is less than an olive-bulk of flesh or marrow.

And furthermore, if the mishna is discussing a case where there is not an olive-bulk of marrow, why do the thigh bone of an unslaughtered carcass and the thigh bone of a creeping animal impart impurity in a case when they were perforated?

The Gemara answers: That is not difficult. The first clause of the mishna, which discusses the thigh bone of a corpse, is referring to a case where there is not an olive-bulk of marrow. The latter clause of the mishna, which discusses the thigh bones of a sacrificial animal, an unslaughtered carcass, and a creeping animal, is referring to a case where there is an olive-bulk of marrow. And accordingly, what is the tanna of the mishna teaching us? He is teaching us several distinct matters separately, as follows.

In the first clause he is teaching us that the marrow inside the bone does not heal the flesh outside the bone. With regard to the thigh bone of sacrificial animals, what is he teaching us? He is teaching us that a bone that serves as a handle or protection for flesh or marrow that became notar is significant and imparts impurity, as Mari bar Avuh said that Rabbi Yitzḥak said: Bones of sacrificial animals that served as a handle for notar, meaning that they have leftover meat on them or inside them after the allotted time for its consumption, transmit impurity to the hands of those who handle them, just as the leftover sacrificial meat itself transmits impurity to the hands. Since the bones have become a base for an intrinsically forbidden object, they are treated in the same manner as the forbidden object itself.

Next, the tanna of the mishna teaches that with regard to the thigh bone of an unslaughtered carcass, even if there is an olive-bulk of marrow inside, if it was perforated it does impart impurity, but if it was not perforated, it does not impart impurity.

Abaye said: Actually, the tanna of the mishna maintains that marrow inside the bone heals the flesh outside the bone. And with regard to the consequent assertion: If so, the thigh bone should impart impurity in a tent as well, the explanation is that here we are dealing with a case where one scraped the bone. Therefore, the flesh and the marrow can no longer heal, and the bone is not considered a proper limb that imparts impurity in a tent.

And this mishna is in accordance with the opinion of Rabbi Elazar, as Rabbi Elazar said: A thigh bone that one scraped lengthwise is impure like a limb. Even if it is not attached to flesh or marrow, a bone scraped in such a manner still has the ability to heal. But if one scraped it widthwise it will not heal and is therefore pure. And your mnemonic to remember which can heal and which cannot is a palm tree, because if one sawed a strip off of a palm tree lengthwise it can heal, but if one did so widthwise, i.e., one sawed a strip off of the circumference of the tree, the flow of sap is disrupted and the tree cannot heal.

And Rabbi Yoḥanan said: Actually, the mishna is discussing a case where there is an olive-bulk of marrow in the bone. And the tanna of the mishna also holds that marrow inside the bone heals the flesh outside the bone. And as for the consequent assertion: If so, the bone should transmit impurity in a tent, in fact the bone does impart impurity in a tent. And to what is the mishna referring when it teaches that one who touches the bone is ritually impure? It is also referring to one who overlies the bone.

The Gemara asks: But if the marrow inside the bone heals the flesh outside the bone, why does the mishna teach that the thigh bone of a carcass and the thigh bone of a creeping animal are pure when they were not perforated?

Rabbi Binyamin bar Giddel said that Rabbi Yoḥanan said: Here we are dealing with a case where there is an olive-bulk of marrow that has become detached and is rattling inside the bone. With regard to impurity imparted by a corpse, the impurity breaks through the bone and ascends, and it therefore transmits impurity in a tent. But with regard to the impurity of a carcass, since the marrow is loose and rattling, it will not heal. Therefore, if the bone was perforated and it is possible to touch the marrow, the bone does impart impurity. But if the bone was not perforated it does not impart impurity.

According to Rabbi Yoḥanan, overlying is referred to as touching in the mishna. Rabbi Avin said, and some say it was Rabbi Yosei bar Avin who said: We learn in a mishna as well (Oholot 3:1): In the case of one who touches with one hand half an olive-bulk of a corpse and simultaneously his other hand overlies half an olive-bulk or half an olive-bulk of flesh from a corpse overlies him, he is impure.

Granted, if you say that impurity via contact and impurity transmitted in a tent or to one overlying a part of the corpse are one concept, it is due to that reason that the half olive-bulk of impurity that he touched and the half olive-bulk of impurity that he overlaid join together to constitute the requisite measure of an olive-bulk.

But if you say that they are two concepts, how can they join together? But didn’t we learn in that mishna (Oholot 3:1): This is the principle: Any impure items lacking the requisite volume to have impure status on their own that are of one concept join together and are impure; if they are of two concepts, they do not join together and remain pure?Apparently, touching and overlying a corpse create the same type of impurity, and therefore overlying is referred to as touching in the mishna here.

The Gemara challenges: Rather, what is the alternative? Is it one concept that comprises both touching and overlying? Say the latter clause of the mishna in tractate Oholot: But