Answer #1: The bones are Yados. Rav holds like Yehudah.

Answer #2: The bones are Shomrim. Rav holds like Chachamim.

R. Yochanan explains that the bones are Yados. he holds like Chachamim. (Rashi - he must explain this way; Tosfos - he could also say that the bones are Shomrim, like Chachamim.)

(Beraisa - R. Yehudah): If a femur (thigh bone) holds a k'Zayis of meat, the entire bone brings Tum'ah and is Metamei;

Others say, if there is even k'Ful of meat, the bone conducts Tum'ah.

Question: How will Rav establish the Beraisa?

If the bone is a Yad (the meat is on it), why do Others say that k'Ful of meat is enough?!

If the bone is a Shomer (the meat is inside), why does R. Yehudah require a k'Zayis?!

Answer #1: The bone is a Yad. Rav holds like R. Yehudah.

Answer #2: The bone is a Shomer. Rav holds like Others.

R. Yochanan holds like Others. The bone is a Shomer. (The law is true also if it is a Yad. We will explain why we prefer to establish the case to be a Shomer.)

Question: Others require k'Ful of meat. R. Yochanan holds that Shomrim apply even to less than this!

Answer: Really, Others don't require k'Ful. Since R. Yehudah specified a quantity, they also did.

Support (Rava): Presumably, the Beraisa discusses a Shomer, since it mentions the femur, which always has marrow.

(R. Chanina): Others require k'Ful. This is the minimal quantity for Shomrim.

(R. Yochanan): This is not a minimal quantity.

Question: Others say 'if there is even k'Ful...'!

Answer: Since R. Yehudah specified a quantity, they also did.

Question (against R. Chanina - Mishnah - R. Eliezer ben Azaryah): A bean pod is Tahor (does not conduct Tum'ah. A Shomer is not needed, since beans can be cleaned if they get dirty);

A pea pod is Tamei (conducts Tum'ah like a Shomer), because people want Mishmushan (to touch the peas through the pods, for peas cannot be cleaned if they get dirty).

(Peas are smaller than beans. The Reisha of this Mishnah says that even if one pea remains, the pod is Tamei!)

Answer: We answer like Rav Acha brei d'Rava said (elsewhere). The stalk is Tamei like a Yad. (It holds many pods, at least a k'Zayis of food in all. The Mishnah never called it a Shomer. That was merely our understanding.)

The Mishnah is Metamei because people want Tashmishan (to use the stalks, i.e. to move the peas).

Question (Beraisa - Tana d'Vei R. Yishmael): "Al Kol Zera Zeru'a Asher Yizare'a" discusses the way people plant, in which the wheat, barley or lentils are still in their shells. (Even though a lentil is smaller than a bean, the shell is a Shomer!)

Answer: The law of Shomer applies to a Briyah (something complete like it was created) of any size.

Question (R. Oshaya): Can two Shomrim join to the food inside to comprise the Shi'ur of k'Beitzah?

Question: What is the case?

If one Shomer guards the other, the outer Shomer does not have the law of a Shomer!

(Mishnah - R. Yehudah): The innermost of the three outermost shells of onions joins (to k'Beitzah) whether or not it has a hole;

The middle shell joins only if it does not have a hole;

The outer shell does not join even if it has no hole.

Answer: The Shomer was cut into two pieces.

Since each piece does not protect the food on the other side, they are not considered Shomrim;

Or, since each piece protects the food on its side, they are considered Shomrim.

Answer #1 (Mishnah - R. Eliezer ben Azaryah): A bean pod is Tahor. Pea pods are Tamei, because people want Mishmushan. (Therefore, the pods are Shomrim. Even though each pod is less than k'Beitzah, they join to comprise the Shi'ur, even though each pod does not protect peas in another pod!)

Rejection (Rav Acha brei d'Rava): (The Mishnah does not say that pods join, rather, it teaches that) the stalk is Tamei like a Yad.

It is Tamei because people want Tashmishan.

Answer #2 (Beraisa - Tana d'Vei R. Yishmael): "Al Kol Zera Zeru'a Asher Yizare'a" discusses the way people plant, the wheat, barley or lentils are still in their shells. (Even though a shell does not protect seeds in another shell, they join to be a k'Beitzah.)

Rejection #1: Just like Rav Acha brei d'Rava answered (above), that the stalk is Tamei like a Yad, we can say that the stalk is a Shomer on all the ears.

Question: Granted, the lower blades of grain protect the higher ones. (If a shell would fall off, the one above it would fall off);

However, the higher blades do not guard the lower ones! (Even so, they are considered Shomrim.)

Answer: The case is, they are all at the same height on the stalk. (If any one was removed, the others could fall out.)

Question: Could the grain at one height have the volume of an egg?!

Answer: Yes, for example the wheat in the days of Shimon ben Shetach. (It was as big as kidneys of an ox.)

Rejection #2: Here also, the wheat is like wheat in the days of Shimon ben Shetach (each kernel is the volume of an egg, they need not join).

Version #1 - (Beraisa): (There were two bones from a Mes. Each held half a k'Zayis of flesh.) If part of each bone without the flesh was brought into a house, the house is Tamei;

Yehudah ben Nekusa says, they cannot join to be a k'Zayis.

(Reish Lakish): A bone is a Yad, but a hair is not.

(R. Yochanan): Even hair is a Yad.

Question (R. Yochanan - Mishnah): If skin (of a Nevelah) holds a k'Zayis of meat, one who touches a strand of meat or a hair opposite the meat becomes Tamei.

Suggestion: The hair is Metamei because it is a Yad.

Answer: No, it is a Shomer.

Version #1A - Question: Can there be a Shomer (hair) for a Shomer (the skin)?

Answer #1: Hair is rooted in the skin. If the hair was removed, there would be a hole, and the meat would rot. (Therefore, hair itself is a Shomer for the meat.)

Question (Rav Acha bar Yakov): If so (there are holes in hide when the hairs are removed), how can we write Tefilin? We (expound "u'Chsavtam" to) require Kesivah Tamah (a pure writing, without holes in the parchment)!

Answer: We answer like Chachamim of Eretz Yisrael taught, that we are not concerned for any hole that the ink passes over. (I.e. no hole will be seen in the letter.)

Answer #2: The hair is a Yad;

R. Ila'a taught that when there are many strands at the top of a sheaf, each is a Yad, because one can take the sheaf by grasping many strands together. Similarly, when there are many hairs, each is a Yad, because one can take the skin with the meat by grasping many hairs together.

Question: Where was R. Ila'a's law taught?

Answer (Mishnah): Strands at the top of sheaves bring Tum'ah and are Metamei, but they do not join for Shi'ur Tum'ah.

Question: What can the strands be used for? (Why are they Yados?)

Answer (R. Ila'a): The case is, there are many strands at the top of a sheaf. (One can take the sheaf through holding all the strands.)

Version #1B - Support: Presumably, the hair is a Shomer. One hair cannot serve like a Yad!

Rejection: Really, the hair is a Yad;

R. Ila'a taught that when there are many strands at the top of a sheaf, each is a Yad, because one can take the sheaf through all the strands. Similarly, when there are many hairs, each is a Yad.

Question: Where was R. Ila'a's law taught?

Answer (Mishnah): Strands at the top of sheaves conduct Tum'ah, but they do not join up.

Question: What can the strands be used for? (Why are they like Yados?)

Answer (R. Ila'a): The case is, there are many strands at the top of a sheaf.