(Mishnah): If a Kohen married...

(Beraisa): He vows (not to benefit from her), performs the Avodah, and divorces her after finishing the Avodah.

Question: We should be concerned lest he go to a Chacham to permit his vow!

Answer #1: Our Tana holds that one must be Mefaret (tell all details of) a vow before a Chacham may permit it.

Question: This is like the opinion that one must be Mefaret a vow. According to the opinion that one need not be Mefaret, how can we answer?

Answer #2: He must vow b'Rabim (in front of many people).

Question: This is like the opinion that a vow b'Rabim cannot be permitted. According to the opinion that it can be permitted, how can we answer?

Answer #3: He must vow Al Da'as Rabim (according to the will of many people);

(Ameimar): Even according to the opinion that a vow b'Rabim can be permitted, a vow Al Da'as Rabim cannot be permitted.

It cannot be permitted for Reshus, but it can be permitted for a Mitzvah.

There was a teacher (of children) who used to strike his students too much. Rav Acha made him vow Al Da'as Rabim that he would not teach children again;

Ravina (annulled the vow and) reinstated him, because he could not find someone else that taught so precisely.

(Mishnah): If a Kohen (habitually) becomes Tamei Mes...

Question: Why does it suffice for him merely to accept not to do so again, but a Kohen in a forbidden marriage must vow?

Answer: There is less temptation to become Tamei, so we are not concerned lest he not honor his acceptance.

(Mishnah): A boy can be a Bechor regarding inheritance (to get a double portion), but not regarding (the Mitzvah to be redeemed by giving five Shekalim to a) Kohen;

One can be a Bechor for Kohen, but not for inheritance;

One can be a Bechor for both, or for neither.

The following are Bechoros only for inheritance:

He was born after a Nefel (non-viable baby), even if the Nefel was alive when its head left womb;

He was born after a nine month (viable) baby that died before its head left womb;

R. Meir says also one who was born after a miscarriage of a baby (with a face) resembling a Chayah, Behemah or bird;

Chachamim say, the first must have a human form (if not, the next is a Bechor for both).

He was born after a miscarriage of a Sandal (a fetus that was mashed, it lost its shape), Shilya (fetal sac) or Shefir Merukam (the outer skin of a fetus before bones form);

He was born after a baby whose limbs came out disconnected.

He is the first child of a man who married a woman with children (from a previous marriage).

He is the first child of a Nochris or slave after her conversion or freedom, she had previous children.

R. Yosi ha'Gelili says the first child (after conversion or freedom) is a Bechor even regarding Pidyon, for this depends on "Peter (Kol) Rechem bi'Venei Yisrael" (her first birth when she is a Yisraelis.)

In the following cases, the (next) child will be a Bechor for Pidyon, but not for inheritance;

A man with children married a woman without children;

A pregnant Nochris or slave (who had not yet given birth) converted or was freed.

A woman gave birth for the first time, the baby became mixed up with a baby (who is exempt from Pidyon, i.e.) of a Kohenes, Leviyah or a woman with previous children;

A widow or divorcee remarried within three months (and gave birth within nine months after leaving her first husband). We do not know whether it is a nine-month baby from her first husband, or a seven-month baby from her new husband. (The son must redeem himself when he grows up.)

(Gemara - Shmuel): If the head of a Nefel left the womb, this is not considered birth (to exempt the next baby from Pidyon).

Question: What is the reason?

Answer: "Kol Asher Nishmas Ru'ach Chayim b'Apav" - the nose (or head) is important only regarding something that can live.

Question (Mishnah): A baby born after a Nefel whose head came out alive, or after a nine-month baby whose head came out dead (is a Bechor for inheritance, but not for Pidyon).

This shows that birth of a Nefel's head is considered birth regarding Pidyon!

Answer: "Head" really refers to the majority of the body.

Question: If so, why didn't the Tana explicitly say this?

Answer: He said "head" for parallel structure with the Seifa, which discusses a nine-month baby whose head came out dead;

There, he needed to say "head", so we can infer that had the head came out alive, the next child would not be a Bechor for inheritance, and not for Pidyon.

Question: The Chidush (that we infer from the Seifa) is that birth of the head of a viable baby is considered (full) birth. Another Mishnah teaches this!

(Mishnah): If it stuck out its head, even if it returned it, it is as if the fetus was born.

Suggestion: Perhaps that teaches about an animal, and our Mishnah teaches about a human.

Rejection: Another Mishnah teaches this (regarding people)!

(Mishnah): If a baby is born normally (head-first), once the majority of the head comes out, i.e. the forehead, it is considered born.

Shmuel is refuted. (Sefas Emes asks that surely, Shmuel knew the Mishnah! He answers that Shmuel holds like Reish Lakish (below) that the forehead is not enough to be considered birth regarding inheritance. We do not learn this from the other Mishnah. The Gemara holds like R. Yochanan, therefore it says that Shmuel is refuted.)

(Reish Lakish): Emergence of the forehead is considered birth in every respect except for inheritance, for it says "Yakir" (the entire face must leave for proper recognition);

(R. Yochanan): It is enough even regarding inheritance.

Question: What does Reish Lakish include by saying "in every respect"?

Answer: He teaches like the following Beraisa:

(Beraisa): If a Nochris was giving birth, and the forehead came out, and then she converted, and then the entire baby came out, Tum'ah and Korban of a Yoledes do not apply to her (because Halachic birth preceded her conversion).

Question (against R. Yochanan - Beraisa): "Yakir" refers to recognition of the face, i.e. with the nose.

Answer: It should say "until (but not including) the nose."

Question (Mishnah): To give Edus Ishah (to testify that a man died to permit his widow to remarry), one must see the face with the nose. (This is difficult even for Reish Lakish, who says that the forehead suffices for everything except for inheritance!)

Answer #1: It should say "until the nose."

Question (Mishnah): One cannot testify that a man died if he saw only the face or forehead. He must see both, with the nose.

(Abaye): We learn from "Hakaras Panim Ansah Bam."

Answer #1: (Normally, the forehead suffices.) Chachamim were more stringent about Edus Ishah.

Objection: Chachamim were more lenient about Edus Ishah than normal testimony!

(Mishnah): It became established to accept (for Edus Ishah) Ed mi'Pi Ed (one testifies about what he heard from a witness), or (even) what one heard from a woman or slave.

Answer #2 (to both questions): Chachamim were more lenient about who may testify, but they were more stringent about what the witness must see.

Answer #3 (to both questions): "Hakaras Panim" requires the face, forehead and nose to identify a person (Shev Shemaitsa 7:16 - through Simanim, e.g. a long, flat nose, for one who does not recognize the person), "Yakir" does not require this.