Citation (54a): We know from reasoning [that one may not murder in order to save himself]. Who says that your blood is redder [than the victim's]?

This applies only when they coerce him to overtly kill. If they want to throw him on a baby, and this will crush the baby, just the contrary! We can say oppositely;

Who says that his colleague's blood is redder [than his? Why should he forfeit his life to save his colleague?]

Since he does not overtly kill, and he is mere Karka Olam, he is not commanded to save his colleague with his body. Just the contrary, his own life has precedence!

Explanation: The Hekesh is in a verse written about one who ok9 - "Ki ka'Asher Yakum Ish Al Re'ehu..."

Opinion #1: Now, the text in all places is "just like a murderer, Yehareg v'Al Ya'avor, also Na'arah Me'orasah Yehareg v'Al Ya'avor", i.e. the Bo'el;

The text does not say Tehareg (she must submit to be killed), for she is Karka Olam.

Opinion #2 (Ri): Even if the text says Tehareg, we can explain that she must submit to be killed rather than do an action and bring the Ervah upon herself.

Question: In Avodah Zarah (54a), it says that something Ne'evad (worshipped) b'Ones is forbidden. It explains that the case is, Nochrim coerced him to bow to his animal;

Citation (54a) Question (R. Zeira): The Torah exempted Ones - "vela'Na'arah Lo Sa'aseh Davar"!

Summation of Tosfos' question: What is difficult? The verse discusses only Karka Olam, but if one did an action, he is obligated to forfeit his life, like I explained!

One who bows to an animal does an action. We cannot say that this is when Nochrim bent him to idolatry, for this is not bowing!

Answer #1 (Ri): He asks that the Torah exempted Ones from death, even if he does an action. Granted, he is obligated to be Moser Nefesh, but if he was not, he is not Chayav Misah;

"Vela'Na'arah Lo Sa'aseh Davar" applies even if she did an action, and the verse exempts from Misah. The Hekesh applies to doing an action.

Answer #2: Further, since even b'Ratzon one is Chayav Misah even without doing an action, for a woman is liable b'Ratzon, even though she is Karka Olam.

Also here, when the Torah exempts from Misas Beis Din, like it says "vela'Na'arah Lo Sa'aseh Davar", it is in every case, whether or not he did an action.

Therefore, we ask since he is exempt from death, it is not considered Ne'evad to be forbidden through this Avodah.

He answers that there it is considered Ne'evad b'Ones, even though he is exempt from death b'Di'eved, since he was obligated to be Moser Nefesh.

Explanation #1 (Rashi): This is because he has no Da'as (intelligence, while sleeping).

Objection: A minor, even though he has no Da'as, would have acquired, had a verse not excluded him!

Explanation #2: Rather, it is because he did not intend for Bi'ah at all. He is like one who intended to press his Ever against the wall, brought below.

Question: We need this to teach Bi'ah with a Yevamah. It is written only here!

Answer: We learn [Bi'ah] from "Lehakim l'Achiv Shem."

Answer: Still, we need [Yevamah Yavo Aleha] for the Gezeirah Shavah below (55b). What is the source that a Yevamah is acquired through Ha'ara'ah? We learn from "Bi'ah-Bi'ah."

Answer: Bi'ah of Chayavei Lavin is Mufneh (extra). It is Mufneh from one side. (We need Bi'ah of Yevamah Yavo Aleha to teach whether Shogeg...)

Explanation: This is not precise, for below we say that if he intended to have Bi'ah with an animal, and had Bi'ah with his Yevamah, he acquired her.

Question: In Kidushin (67b), we wanted to learn that Kidushin is not Tofsin in all Arayos from Achos Ishto, and we said "granted, we could learn all of them..."

How could we learn all of them? We can ask that he can increase the Isur Achos Ishto [through marrying more women]!

Answer #1: Even without this, we asked properly [there].

Answer #2: Only regarding Eshes Ach, we consider "it is possible to increase it" to be a stringency, for he can increase the Isur on others;

What a person can increase Isur to himself (e.g. Achos Ishto) is not considered a challenge.

Question (Rivan): From Achos Av v'Em, we can learn an Isur that comes automatically, and from Eshes Ach we can learn an Isur that comes through Kidushin!

Answer: We cannot learn Eshes Ish, like we ask below, "we cannot learn from the others, for they are She'er."

Explanation: Since the Torah permitted her after death, it is unreasonable that she is forbidden in his lifetime.

It is unreasonable that the verse comes to teach that an Aseh is Docheh a Lo Sa'aseh with Kares, unless it is explicitly proven from a verse.

Implied question: Why don't we learn [Bi'ah with] a male or animal from R. Yonah's Hekesh?

Answer #1: [The source for Ha'ara'ah] says "Es Mekorah He'erah." Makor does not apply to them.

Answer #2: The verse of Molech interrupts [between the Arayos and a male or animal].

Answer #3: [Bi'ah with] a male or animal is not considered Bi'ah, for it is not normal.

Support: This is why in Sanhedrin (54b), we need a warning and punishment for the Shochev (one who inserts his Ever) and Nishkav (a male into whom it was inserted), even though normally we do not need a verse to obligate an Ishah who is Nishkeves.

Implied question: It would suffice to teach about three [to teach that one is forbidden to his wife's half-sisters!]

Answer: The Mishnah teaches that even though there is a mixture, and all five are a chain [of half-sisters], and one must divorce the forbidden wives, we do not decree to forbid the permitted wives due to the forbidden wives.

Explanation: It needs to teach this. One might have thought that it is better to decree to do Chalitzah to the Tzaros (other wives of this man not related to the half-sisters), lest one do Chalitzah to the second or fourth wives (who are not really married to him, so they do not exempt anyone).