Zevachim 116a: We know that Noach did not bring Treifos in the ark, because it says "Itach (with you, i.e. like you)".

Question: Perhaps No'ach himself was Treifah!

Answer: If so, Hash-m would not have asked him to bring animals (Treifos) like himself!

Yevamos 121a (Mishnah): A case occurred in Asya in which a man was lowered into water. When they lifted him, only his leg came up. Chachamim ruled that his wife may remarry only if more than the knee came up.

43a (Beraisa - R. Yosi b'Rebbi Yehudah): If the gall bladder was punctured, it is Tereifah.

Chachamim: Iyov said "my gall bladder spills to the ground", yet he lived!

R. Yosi: We cannot learn from miraculous cases. Iyov's kidneys were stricken. According to nature, he could not survive. He was kept alive miraculously - "just guard his soul (that he will not die)."

57b (Beraisa): If there is a long hole in the skull, or many small holes that add up to the area of a drill (it is Tereifah);

R. Yosi ben ha'Meshulam says, a case occurred in which a man's skull was pierced. They covered over it with a gourd, and he lived.

R. Shimon ben Elazar: This is not proof (that this is not a Tereifah). He was hurt in summer, and he died that winter!

Gitin 56b: A mosquito entered Titus' nose and bored into his brain for seven years.

Rambam (Hilchos Gerushin 13:16): if a man was cast into water, and they sent a trap after him, and came up a limb that he cannot live without it, we may testify that he died to permit his wife to remarry.

Magid Mishneh: The Ramban and Rashba say that they permitted the man only after 12 months. Also the Yerushalmi says so.

Question (Kesef Mishneh): In Chulin we say that a human Tereifah can live more than 12 months.

Tosfos (Zevachim 116a DH Dilma): How could the Gemara suggest that No'ach was Treifah? He lived another 300 years after the flood! Perhaps the Gemara means that he did not have proper strength and health. Our Sugya is like the opinion that a Tereifah can live. R. Tam distinguishes Tereifos of people from that of animals. Man can live longer, for he has Mazel. This is difficult, for Chulin 43a learns man from animals!

Birkas ha'Zevach: R. Tam will explain that Noach had a blemish such as a punctured membrane, which makes an animal Tereifah, but does not make a person Tereifah. Surely a human Tereifah cannot live more than 12 months, just like an animal Tereifah! The Kesef Mishneh says that a human Tereifah can live more than 12 months. Surely no one says so according to the opinion that a Tereifah cannot live. This is a printing mistake in the Kesef Mishneh. This is why he did not write anything like this in the Beis Yosef or Shulchan Aruch.

Chasam Sofer (YD 52): In any case, we must say that there is a printing mistake in the Kesef Mishneh. If a human Tereifah can live more than 12 months, why does the Mishnah permit his wife? When did they permit her? In Yevamos, the Ramban, Rashba and Ritva say that not all Tereifos of animals are Tereifah in people. The Mishnah needed to say that Tereifos in animals are Tereifos in birds. If not for this, we would distinguish them, since their natures are different. All the more so, we may distinguish man from animals. What was the question from Iyov? In any case, what was the question? He was punished only for 12 months (Eduyos 2:10). Do not say that we asked from the fact that he lived for another 140 years after this, without thinking that miracles are different. In truth, his gall bladder did not spill to the ground, just he felt as if it were due to his afflictions. We asked how he could say so, for if it spilled, he could not live! Rather, man is weaker than animals. Anything that would kill an animal would surely kill a person, even in less than 12 months. However, man has Mazel, so for some Tereifos a cure can help, even though they do not help for animals. We asked, for no cure was done for Iyov, like (the coming) Tosfos said.

Tosfos (Chulin 43a DH Yiflach): Rashi says that Iyov's kidneys were stricken in a way that makes them Tereifah. What was the source to assume so and ask how he lived? Rather, whenever the kidneys are stricken one cannot live without a cure, and we do not see that Iyov received a cure.

Rambam (Hilchos Rotze'ach 2:8): Beis Din does not kill one who kills a Tereifah. Every person is Muchzak to be healthy unless we know that he is a Tereifah and doctors know no cure and his defect will kill him.

Aruch ha'Shulchan (CM 425:17): Even if we know that he has a Tereifah injury, until the doctors despair, we assume that he is from the majority of healthy people. Likewise, if an animal has a lesion in the lung (and we are unsure if it is Tereifah), we follow the majority of animals, which are Kosher. The Rambam refutes those who say otherwise.

Rebuttal (Minchas Chinuch 34 DH veha'Ram): There is no source for the Rambam from the Gemara. He said so from reasoning. However, he connotes that if one killed a Tereifah before doctors examined whether there is a cure for him, he is liable. This is unreasonable. Since he is Tereifah, presumably there is no cure! He should be exempt unless doctors say that there is a cure. The majority of Stam people are not Tereifos, but if we know that he is a Tereifah, Stam there is no cure!

Achiezer (1:12:5): A Tereifah has no Chazakah that it is still alive, e.g. if we see a hole in the membrane of the brain. Regarding an internal sickness that is not clear to doctors, it is like one who is dangerously sick, who has a Chazakah of being alive. The Rambam says that everyone has a Chazakah to be healthy, and one who kills him is killed, unless we surely know that he was a Tereifah and the doctors say that there is no cure. Surely, if doctors say about a Stam Choleh that there is no cure, he is not a Tereifah. He is a Goses, and one who kills him is killed. Rather, the Rambam discusses a Tereifah, and also requires that doctors say that there is no cure. If not, he is not considered a Tereifah. We cannot add to Tereifos what can be cured (Chulin 54a). However, when we have a tradition about a Tereifah, a cure does not change anything. However, there is no tradition for people; one is exempt for a Tereifah only if the doctors say that he cannot be cured. If an operation would help, he is not a Tereifah. Why does the Ramban say that a leg cut at Tzomes ha'Gidim is Tereifah? If one will cut above, it will live! A cure is in our hands! He must say that the tradition is that it is a Tereifah, even though if we will cut above it will become Kosher. This is only for animals, for which there is the tradition, but not for people.

Igros Moshe (CM 2:73:4): Animals are permitted based on the Tereifos established the days of the Gemara. One is liable for murder only if contemporary doctors know no cure. Nowadays Beis Din does not kill people; it is proper to fine one for killing a Tereifah like for a healthy person.

Shulchan Aruch (EH 17:32): If a rope was tied around a man's leg and he was lowered into water, and only the leg came up (and part is) above the thigh, his wife may remarry after 12 months, for a Tereifah cannot live 12 months.

Pri Megadim (Sifsei Da'as YD 31:1): According to the Yam Shel Shlomo, 12 months should not permit a widow to remarry, for there is a Chazakah of Eshes Ish, and a minority that live more than 12 months. Mid'Rabanan, this is like an even Safek! We must say that the Mishnah permitted because water worsens the wound, or because Chachamim knew that for this Tereifah, no one will ever live more than 12 months.

Pleisi (YD 31:5): A human Tereifah can live more than 12 months. The Yerushalmi said that they permitted the widow after 12 months, and derived that a Tereifah does not live. This is like the Yam Shel Shlomo, that most Tereifos do not live 12 months. We rely on the majority for Agunos.

Chazon Ish (EH 27:3): The Rambam says that it is easier to cure man than animals. This explains why people have operations on the intestines and live long lives. Therefore, we cannot accept testimony about other Tereifos (to permit widows to remarry). Even if doctors do not know a cure, perhaps there is a cure, and some doctor will find it.