with regard to those animals enumerated by the Sages as having skin, since their skin is considered by the Sages to be similar to their flesh. The Gemara asks: On the contrary, those that the Sages enumerated, whose skin and flesh are equated, do not have skins. And Abaye said: This is what the tanna in the baraita is saying: Only those that the Sages did not enumerate have skin discrete from their flesh. Rava said to him: Doesn’t the baraita say the opposite: That those enumerated by the Sages have skin discrete from their flesh? Rather, Rava said: This is what the baraita is saying: Only the skin of those animals enumerated by the Sages transmits impurity like flesh. The Gemara asks: Is that to say by inference that Rabbi Yoḥanan ben Nuri holds that even the creeping animals not enumerated by the Sages also transmit impurity? Isn’t the opposite taught, that Rabbi Yoḥanan ben Nuri says: The eight creeping animals have skin that does not transmit impurity? Rav Adda bar Mattana said to resolve it this way: And the Rabbis say: With regard to impurity, those animals enumerated by the Sages do not have skin. According to this explanation, Rabbi Yoḥanan ben Nuri and the Rabbis disagree only with regard to the laws of impurity.

But still, is it clear that they do not disagree with regard to the matter of Shabbat? Wasn’t it taught in a baraita: One who traps one of the eight creeping animals mentioned in the Torah on Shabbat is liable, as is one who wounds them, if they are creeping animals that have skins? And what is considered to be an irreversible wound? It is a wound where the blood collects in a single spot beneath the skin, even if it does not emerge. Rabbi Yoḥanan ben Nuri says: The eight creeping animals have skins. Apparently, there is disagreement with regard to Shabbat as well.

Rav Ashi said: Who is the first tanna? It is Rabbi Yehuda, who follows the texture of the skin. He does not distinguish between those creeping animals whose skin is considered like flesh and those whose skin is discrete from the flesh as the verses may imply; rather, creeping animals are distinguished based on the texture of their skin, as we learned in a mishna that Rabbi Yehuda says: Even though the lizard is mentioned in the verse, it has the same ruling as the weasel because the weasel has skin discrete from its flesh. However, the Rabbis, who disagree with Rabbi Yoḥanan with regard to impurity, concede with regard to Shabbat and hold that all creeping animals have skins. The Gemara asks: If so, the phrase in the baraita: This is the statement of Rabbi Yoḥanan ben Nuri, is difficult. It should have said: This is the statement of Rabbi Yoḥanan ben Nuri and those who disagree with him, as the Rabbis who disagree with him with regard to impurity concede to him with regard to the laws of Shabbat. The Gemara responds: This is not difficult. Emend the baraita and teach: The statement of Rabbi Yoḥanan ben Nuri and those who disagree with him.

Levi raised a dilemma before Rabbi Yehuda HaNasi: From where is it derived that a wound is defined as something irreversible? He answered him that it is derived as it is written: “Can a Cushite change his skin, or a leopard its spots [ḥavarburotav]?” (Jeremiah 13:23). The Gemara explains: What does ḥavarburotav mean? If you say that they are spotted marks on the leopard’s skin, that phrase: Or a leopard its spots, should have been: Or a leopard its colors. Rather, ḥavarburotav means wounds, and they are similar to the skin of a Cushite: Just like the skin of a Cushite will not change its color to white, so too a wound is something that does not reverse.

We learned in the mishna: And one who traps other abominations is exempt. The Gemara infers: If one kills them he is liable. The Gemara asks: Who is the tanna who holds this opinion? Rabbi Yirmeya said: It is the opinion of Rabbi Eliezer, as it was taught in a baraita that Rabbi Eliezer says: One who kills lice on Shabbat is akin to one who kills a camel on Shabbat. Apparently, he is the Sage who holds that one is liable for killing any living creature. Rav Yosef strongly objects to this: Perhaps this is not so, as the Rabbis disagree with Rabbi Eliezer only with regard to lice, which do not procreate. However, with regard to other abominations and crawling things that procreate, they do not disagree with him.

And fundamentally they both derived this halakha from the reddened ram skins used to cover the Tabernacle. Rabbi Eliezer holds that liability for killing an animal on Shabbat exists only with regard to animals like rams. Just as rams have their lives taken and die, so too, one is liable for killing any animal whose life is taken, including lice. And the Rabbis also hold that liability for killing an animal on Shabbat exists only with regard to animals like rams. Just as rams procreate, so too, one is liable for killing any creature that procreates. One is not liable for killing lice, which do not procreate. Abaye said to Rav Yosef: And lice do not procreate? Didn’t the Master say: The Holy One, Blessed be He, sits and sustains everything from the horns of wild oxen to the eggs of lice? Apparently, lice reproduce by laying eggs. Rav Yosef answered him: There is a species of insect that is called lice eggs, but lice themselves do not actually lay eggs.

Again he asked: And wasn’t it taught in the baraita that lists types of creeping animals: Tefuyei, a type of insect, and lice eggs? He answered him: There is a species of insect called lice eggs. Again he asked: And still, there is the issue of a flea, which procreates according to all opinions, and nevertheless, it was taught in a baraita: With regard to one who traps a flea on Shabbat, Rabbi Eliezer deems him liable and Rabbi Yehoshua deems him exempt. Rav Ashi said: Are you raising a contradiction between trapping with killing? Rabbi Eliezer and Rabbi Yehoshua disagree only in that one Sage, Rabbi Eliezer, holds that one is liable for trapping even a species that is not typically trapped; and one Sage, Rabbi Yehoshua, holds that one is exempt in that case. However, with regard to killing, even Rabbi Yehoshua concedes that one is liable.

We learned in the mishna that one who traps creeping animals for a specific need is liable, but one who traps them for no specific need is exempt. The Gemara asks: Who is the tanna who holds this way? Rav Yehuda said that Rav said: It is Rabbi Shimon, who said that for a prohibited labor performed not for its own sake, one is exempt.

Some taught the statement of Rav in reference to this: With regard to one who drains an abscess in a boil containing pus on Shabbat, if his intention is to create an opening for it he is liable; if his intention is to remove pus from it he is exempt. The Gemara asks: Who is the tanna who holds this way? Rav Yehuda said that Rav said: It is Rabbi Shimon, who said that for a prohibited labor performed not for its own sake, one is exempt.

Some teach the statement of Rav as referring to this: With regard to one who traps a snake on Shabbat, if he engages in its trapping so it does not bite him, he is exempt; if he does so for medicinal purposes he is liable. The Gemara asks: Who is the tanna who holds this way? Rav Yehuda said that Rav said: It is Rabbi Shimon, who said that for a prohibited labor performed not for its own sake, one is exempt.

Shmuel said: With regard to one who removes a fish from the sea, when an area on the skin of the fish has dried up the size of a sela, he is liable. A fish in that condition cannot survive, and therefore the individual who removed it from the water is liable for killing it. Rabbi Yosei bar Avin said: That is so as long as the skin that dried is between its fins. Rav Ashi said: Do not say that this halakha applies only in a case where it actually dried. Rather, it applies even if the fish has dried to the extent that mucus has formed, and if one were to touch that area it would stick to his fingers.

Mar bar Hamdurei said that Shmuel said: One who reached his hand into the innards of an animal on Shabbat and detached a fetus that was in its womb is liable. The Gemara asks: What is the reason for this? It does not make sense to consider the fetus as a full-fledged living creature. Rava said: Bar Hamdurei explained this to me. Didn’t Rav Sheshet say: One who detaches hops on Shabbat from the shrubs and thorns on which they are growing is liable for uprooting an object from its place of growth? Here, too, in the case of the fetus, one is liable for uprooting an object from its place of growth. Abaye said: One who detached