1)

(a)A Beis-ha'Peras (see Tos. Yom-Tov) is - an area in which a grave was plowed up.

(b)It may be called by that name because the Tum'ah is spread out across the field or because of the broken bones that are strewn around there. Alternatively - P'ras refers to the soles of the feet of the people who refrain from walking there on account of the Tum'ah.

2)

(a)The area that is Halachically affected is a M'lo- Ma'anah (an entire furrow) - which is the equivalent of one hundred Amos square (according to the Tana Kama [see Tos. Yom-Tov DH 'M'lo Ma'anah' & 'Ma'anah']).

(b)In that area one can sow - four Sa'in.

(c)We learn this from the Courtyard of the Mishkan - which was half the area in size (a hundred by fifty Amos) and which is described as Beis-Sasayim (two Sa'ah).

(d)The reason for this decree was - due to the suspicion that the plow may have carried bones of the Meis the size of a barley (which are Metamei through touching).

3)

(a)According to R. Yossi disagrees - one can sow five Sa'in there (see Tos. Yom-Tov).

(b)The Mishnah qualifies the above Shi'ur - confining it to where the plow is descending or moving straight, but not where it is ascending, where the Shi'ur will be considerably smaller, according to the Tana Kama.

(c)In that case, we measure it by placing a quarter Kav of oats on the Borech - a knee-shaped hollow piece of wood on to which the plow is fixed, with a hole at the base, through which grains are slowly fed into the earth below as the plow proceeds (see Tos. Yom-Tov).

4)

(a)The end of the Beis-ha'Peras, where the plow is moving upwards is - where no more than three grains (see Tos. Yom-Tov) of vetch (horse-beans) fall from the Borech to lie side by side (see Tos. Yom-Tov DH 'Zeh be'Tzad Zeh').

(b)According to R. Yossi - an upward slope does not have the Din of a Beis-ha'Peras at all ...

(c)... because then any bone that the plow picks up will simply fall off.

(d)The Halachah is - like the Tana Kama.

5)

(a)The Mishnah rules that if one is plowing a Beis ha'Peras and the plow hits a rock or a wall - hard enough to cause it to shake all the accumulated earth from the plow, the Beis-ha'Peras ends there, because the plow will no longer contain bones to scatter beyond that point (even if it is only a few Amos away from the grave).

(b)The third case mentioned by the Tana is - where one deliberately shakes the plow.

6)

(a)When R. Elazar (or R. Eliezer) says that Beis-ha'Peras Oseh Beis ha'Peras, he means that - if someone begins to plow from the end of a Beis-ha'Peras or from the middle, then up to a hundred Amos from that spot has the Din of a Beis-ha'Peras too.

(b)According to R. Yehoshua - a Beis-ha'Peras only makes a Beis-ha'Peras if for example, one stopped after half a M'lo Ma'anah, and then completed the other half (see Tos. Yom-Tov), but beyond the Shi'ur of M'lo Ma'anah, it does not become a Beis-ha'Peras ...

(c)... and when he adds ve'Chein ha'Tzedadin, he means that - the same will apply if one plows fifty Amos in one direction, and another fifty Amos at right-angles to the initial plowing.

(d)The Halachah is - like R. Yehoshua.

7)

(a)The Mishnah rules that if someone plows Milatimya - (a pit full of corpses [the acronym of Malei Tamya ... full of bones] see Tos. Yom-Tov), or ...

1. ... from a Tzeviras ha'Atzamos - (see Tos. Yom-Tov) - an area containing piles of bones, he does not create a Beis-ha'Peras ...

(b)... because it is uncommon to plow such places.

(c)Nor did they include a case where one plowed a field containing a grave ...

1. ... whose whereabouts is unknown - because it is a S'fek S'feika (a double Safek) a. perhaps he did not plow the location of the grave b. even if he did, perhaps he did not drag any bones across the field.

2. ... which was previously unknown - because the Din of Beis-ha'Peras is basically a K'nas (a penalty for spreading Tum'ah in this way), and one cannot penalize someone who is not even aware that a grave exists there.

8)

(a)The Mishnah rules that if ...

1. ... someone plows up a grave in a field that is not his - it does have a Din of a Beis-ha'Peras (because the Chachamim do not punish Shimon for the sins of Reuven).

2. ... a Nochri plows up a grave in his own field (Tos. Yom-Tov) - it does have the Din of a Beis-ha'Peras either (because they do not tend to penalize Nochrim).

(b)When the Tana concludes she'Ein Beis-ha'Peras le'Kutim, he means that - they did not even penalize the Kutim, how much more so, Nochrim.

9)

(a)The Mishnah rules that if a Beis-ha'Peras that is higher than a Tahor field is swamped by rain, which drains into the lower field - the latter does not nbecome a Beis-ha'Peras ...

(b)... even if it initially comprised red earth which now turned white due to the former being washed into it, or vice-versa ...

(c)... because the Chachamim confined the decree of Beis-ha'Peras to the area that is initially plowed up.

10)

(a)The Tana now discusses a house with an attic that has been built in a field which is known to contain a lost grave (see Tos. Yom-Tov). Assuming the entrance to the house is ...

1. ... exactly above the entrance to the house (see end of Tos. Yom-Tov DH 'Aliyah Tehorah') - he rules that the attic Tahor (see Tos. Yom-Tov).

2. ... not above the entrance to the house - he declares it Tamei.

(b)The reason for ...

1. ... the former ruling is - because even if the grave is underneath either the floor of the house or the threshold of its entrance (see the previous Tos. Yom-Tov), the house will be Tamei, but not the attic.

2. ... the latter ruling is - because, should the grave be underneath the wall above which is the entrance to the attic, then we will apply the principle Tum'ah Boka'as ve'Olah, and the Tum'ah will enter the attic via the entrance.

(c)It is obvious that - Mah Nafshach (either way) the ground floor is Tamei.

11)

(a)Both earth from a Beis-ha'Peras and earth from Chutz la'Aretz - are Metamei both be'Maga and be'Masa (via both touching and carrying).

(b)According to R. Eliezer, earth sufficient to seal a commercial leather sack combines to render Tamei. The case is - for example, where a bundle of vegetables is imported consisting of a number of stalks, each with less than the required Shi'ur of earth attached.

(c)The Chachamim - declare it Tahor (unless the full Shi'ur is attached to one of the stalks).

12)

(a)R. Yehudah cites a case where as much as a Sa'ah, or even two Sa'ah, of earth, would arrive from Chutz la'Aretz - in the form of seals on letters addressed to the sons of the Kohanim Gedolim, who were not concerned about Tum'ah (see Tos. Yom-Tov) ...

(b)... a proof for the Chachamim.

(c)The Halachaah is - like the Chachamim.