WHO MAY JUDGE BUT MAY NOT TESTIFY
Answer (R. Yochanan): It refers to someone who is blind in one eye. Our Mishnah is R. Meir:
(Beraisa - R. Meir) Question: "V'Al Pihem Yihyeh Kol Riv v'Chol Naga" -- what is the connection between Riv (Dinim, i.e. monetary cases) and Nega'im (Tzara'as? Rashash - granted, only Kohanim can judge Tzara'as, but why should Kohanim be required for monetary cases?)
Answer: The Torah equates them. Just like the Kohen looks at Tzara'as only during the day ("uv'Yom Hera'os"), also Dinim must be judged during the day.
Also, just like a Kohen who is blind (even in one eye) cannot rule about Tzara'as (for it says "l'Chol Mar'ei Einei ha'Kohen"), a blind person cannot judge Dinim.
We also learn from Dinim to Tzara'as. Just like relatives cannot judge Dinim, they cannot rule about Tzara'as.
Suggestion: Just like we require three judges for Dinim, we should require three Kohanim to rule about Tzara'as!
Support: If three judges are required to take money from a person, all the more so three are required to declare Tzara'as on his body!
Rejection: "V'Huva El Aharon ha'Kohen Oh El Echad" teaches that even one Kohen can rule.
A blind man used to judge in R. Yochanan's neighborhood. R. Yochanan did not say anything.
Question: R. Yochanan said that the Halachah follows a Stam (anonymous) Mishnah, and he himself said that our Stam Mishnah, which says that there is someone Kosher to testify but not to judge, refers to someone blind in one eye! (All the more so, a totally blind person may not judge.)
Answer: R. Yochanan rules like a different Stam Mishnah:
(Mishnah): Monetary cases must be started during the day, one may finish them at night. (Rulings about Tzara'as, which are like a final verdict, must be during the day. This shows that the Tana does not equate Dinim to Tzara'as. Rashi (Sanhedrin) - at night, everyone is like a blind person, yet we may finish Dinim at night.)
Question: Why does he rule like that Stam Mishnah, and not like ours?
Answer #1: That Mishnah is the opinion of many Chachamim. (We do not attribute it to an individual. Our Mishnah is like R. Meir.)
Answer #2: That Mishnah teaches the law among other Dinim.
TO WHAT DO MA'ASER AND PE'AH APPLY?
(Mishnah): Tum'as Ochlim applies to everything from which (Terumos and) Ma'aseros must be taken, but there are things that have Tum'as Ochlim, but are exempt from Ma'aseros.
(Gemara) Question: What has Tum'as Ochlim, but it is exempt from Ma'aseros?
Answer: Meat, fish and eggs are examples.
(Mishnah): Ma'aseros must be taken from everything from which Pe'ah (a corner of the field) must be left (for the poor), but there are things liable to Ma'aser which are exempt from Pe'ah.
(Gemara) Question: What is liable regarding Ma'aseros but is exempt from Pe'ah?
Answer (Mishnah): Pe'ah must be left from any food with the following properties:
People guard it, it grows from the ground, it is harvested at once, it may be stored for a long time
It says "food" to exclude Sefichim (things that grew by themselves, e.g. from seeds that fell) of safflower or woad (a dye);
"People guard it" excludes Hefker. "It grows from the ground" excludes truffles and mushrooms. "It is harvested at once" excludes figs. "It may be stored for a long time" excludes vegetables.
(Mishnah): Ma'aser must be taken from any food that grows from the ground and people guard it.
We do not require that it is harvested at once, or that it may be stored for a long time!
Pe'ah applies to garlic and onions (for they are stored for a long time);
(Mishnah): If there are rows of onions between patches of vegetables, (the vegetables are an interruption, so) Pe'ah must be left for each row;
Chachamim say, one Pe'ah suffices for all the rows.
INTENT FOR TUM'AS OCHLIM
(R. Yochanan): If one planted endives for the sake of animals, then decided that they should be for people, they are not Mekabel Tum'ah until one has intent (that people will eat them) after they are detached.
He holds that intent while they are attached has no effect.
Support (Rava - Mishnah): There are 13 laws of Nivlas Ohf Tahor. One is that it requires intent (to eat it, to join with other food to comprise a Shi'ur for Tum'as Ochlim), but it does not require Hechsher (through a liquid to be Mekabel Tum'as Ochlim. Rashi - also, it is Tamei by itself. It need not touch Tum'ah.)
(Surely, while a Tahor bird was alive one intended to eat it. The intent required is after it died, because) intent mi'Chayim (while it is alive) has no effect. Likewise, intent while something is attached has no effect!
Rejection (R. Zeira): No, the case is the bird fell from above. There was no intent to eat it mi'Chayim. (However, intent mi'Chayim would have sufficed.)
Question (Abaye): There was a case in Yavneh (later on this Daf), in which Chachamim required intent for a chicken. (Surely, it did not fall from the sky!)
Answer #1 (R. Zeira): It was a Tarnegol Bara (a wild chicken. No one had intent mi'Chayim.)
People laughed at this. (The case in Yavneh involved Tum'as Beis ha'Bliyah (due to eating).) It could not be Tarnegol Bara, which is a Tamei bird!
Abaye: When a great Chacham speaks, do not laugh! He means that a hen ran away (and had chicks. No one had intent for them mi'Chayim);
He calls it Bara for it is Ivrai (away) from its owner.
Answer #2 (Rav Papa): It was a Tarnegolta d'Agma ("hen of the swamp," a wild species).
This is like Rav Papa taught elsewhere;
(Rav Papa): Tarnegol (rooster) d'Agma is forbidden. (It is a Tamei species.) Tarnegolta d'Agma is permitted. (It is a Tahor species.)
(Mereimar): (Any bird that is Dores (catches its prey in its claws, or holds its food in its claws while eating, or eats its prey before it dies) is Tamei.) Chachamim subsequently saw Tarnegolta d'Agma be Dores, so they forbade it. It is the species Girusa.
(Beraisa): If a chick fell into a vat of wine (and died) and one intended to remove it and feed it to a Nochri, it is Tamei (has Tum'as Ochlim);
If he intended to feed it to a dog, it is Tahor;
R. Yochanan ben Nuri says, even in this case it is Tamei.
R. Yochanan ben Nuri: A Kal va'Chomer teaches that it is Tamei. It has severe Tum'ah (Beis ha'Bliyah) without intent. All the more so, it has mild Tum'ah (Ochlim) without intent!
Chachamim: You cannot learn from severe Tum'ah, for it is not Yoredes l'Kach (this will be explained), but it is Yored for mild Tum'ah!
R. Yochanan ben Nuri: There was a case in Yavneh of a hen. It is Yoredes l'Kach, yet Chachamim were Metamei!
Chachamim: The case was, there was intent to feed it to Nochrim.
Question: In what case do they argue? (Me'iri - was the case truly in Yavneh (a big city), or in a nearby village?)
If it is in a big city, no one should require intent!
(Mishnah): The following do not require intent (because some people eat them) nor Hechsher -- Nivlas Behemah Tehorah in any place, or Nivlas Ohf Tahor and Chelev in big cities.
Answer #1: They argue about a village.
Question: All agree that intent is needed there!
(Mishnah): The following require intent but not Hechsher -- Nivlas Behemah Teme'ah in any place, and Nivlas Ohf Tahor and Chelev in villages.
Answer #2 (Rav Ze'ira bar Chanina): Really, they argue about a big city. A chick that falls into wine gets spoiled, so it is (not assumed that anyone will eat it,) like in a village.