1)

(a)The Mishnah lists the ten possible scenarios of Nig'ei Batim. The first two comprise a room that becomes Tahor after one week of quarantine - either because the Nega became dimmer or because it disappeared completely.

(b)The owner is nevertheless obligated - to remove the cement that he initially added when he replaced the stricken stone/s from the inside (see Tos. Yom-Tov).

(c)In the second two scenarios - where the Nega became dimmer or disappeared after the second week, the room becomes Tahor after two weeks of quarantine.

(d)This time, besides removing the cement - the owner is also obligated to bring two birds as a Korban (see Tos Yom-Tov).

2)

(a)In scenarios five and six, the Nega spreads after the first week and either returns or doesn't. Initially, the owner must remove the stricken stones, replace them and cement them ('Choletz, ve'Kotzeh ve'Tach'), and quarantine the room for another week.

(b)In the event that the Nega ...

1. ... returns - the room requires demolishing (Nesitzah).

2. ... does not return - the owner must bring two birds.

(c)The seventh and eighth scenarios comprise where the Nega remain unchanged after the first week and either spreads or doesn't during the second. Initially, the room requires a second week, after the stones have been replaced and the new stones cemented (see Tos. Yom-Tov).

(d)In the event that the Nega ...

1. ... spreads - the room requires Nesitzah.

2. ... does not spread - then the owner must bring two birds.

3)

(a)The last two scenarios comprise where the Nega remains unchanged for two weeks - where initially, the owner follows the same procedure vis-a-vis to the room as in all the previous cases (see Tos. Yom-Tov).

(b)In the event that the Nega ...

1. ... spreads - then the room requires Nesitzah.

2. ... does not spread - the owner must bring two birds.

(c)In the cases where the house does not require demolishing, and the Nega returns ...

1. ... before the owner has had a chance to bring his birds - it requires Nesitzah.

2. ... after the owner has brought his birds - it is considered a new Nega, and the Kohen starts from the beginning.

4)

(a)We learned earlier that the Din of 'Choletz, Kotzeh ve'Tach' extends to the corner-stones (see Tos. Yom-Tov) that belong to the Rasha's neighbor too. The Mishnah now rules - that it does not extend to the Din of 'Noteitz'.

(b)The source for this distinction is - the Pasuk which writes the plural with regard to the former ("ve'Chaltzu"), but singular ("es Avanav ve'es Eitzav") with regard to the latter.

(c)And he comments on this distinction - that, in this regard at least, Chalitzah is more stringent than Netitzah.

5)

(a)R. Eliezer draws a distinction between two kinds of stones, one called ...

1. ... 'Rosh' - which means a large stone or block of wood, which is actually shared by both neighbors, the other ...

2. ... 'Pasin' - meaning a smaller stone or block of wood, of which there are two beside each other, one belonging to the Rasha, the other, to his neighbor (see Tos. Yom-Tov).

(b)R. Eliezer is more lenient than the Chachamim regarding Chalitzah - confining the ruling'Choletz Kotzeh ve'Tach to the neighbor's stones only in the case of Rosh (even the half that belongs to the neighbor), but not in the case of the Pasin that is on the side of the neighbor (see Tos. Yom-Tov).

6)

(a)If the lower room in a two-floor house is stricken with Tzara'an - one supports the ceiling (which is not demolished), before demolishing the walls (and the equivalent ruling will apply in the reverse case).

(b)The stone, wood and earth of the ceiling of a room of a one-floor house that is declared Tamei - must be demolished together with the walls.

(c)The Malb'nim are not demolished together with the room. Neither are the S'rigei ha'Chalonos. 'Malb'nim' might mean bricks that cover the roof (see Tos. Yom-Tov & Tiferes Yisrael). Alternatively - it might mean decorative window-frames that are added to the outside of the house but not cemented to it.

(d)'S'rigei ha'Cholonos' are - regular lattice-work window-frames which enable one to see what is going on in the street without being seen (see also Tos. Yom-Tov).

7)

(a)According to R. Yehudah, 'Malbein ha'Banuy al'Gabav'- (a large piece of wood on which one places the beams, to prevent them from rotting) must be demolished too.

(b)The Tana Kama maintains that the Shi'ur Tum'ah of stones, wood and earth of a Tamei house is a k'Zayis. He learn it from the Pasuk in Beha'aloscha "Al Na T'hi ka'Meis" (in connection with the Tzara'as of Miriam), which compares Tum'as Tzara'as to Tum'as Meis (and the Shi'ur Tum'as Maga of Meisim is a k'Zayis)

(c)According to R. Elazar Chisma - the Shi'ur is a Kolshehu.

8)

(a)Both a Bayis Musgar and a Bayis Muchlat are Metamei. A Bayis Musgar is Metamei - be'Ohel (see Tos. Yom-Tov), from the inside.

(b)We learn from the additional "Tamei Hu" that the Torah writes by a Muchlat - that it is Metamei from the outside, be'Maga, too.

(c)What they have in common is - they are both Metamei be'Ohel from the inside (see Tos. Yom-Tov).

9)

(a)The Mishnah rules that if one took stones from a Bayis Musgar to build elsewhere, and the Nega returns to the room from which they were taken - the stones are Tamei and must be removed (see Tos. Yom-Tov).

(b)If the Nega appears on those stones ...

1. ... the initial room - is Tamei Muchlat and must be demolished.

2. ... they must be removed, but only after the second room has been shut for seven days, since it is now declared a Musgar.

10)

(a)R. Elazar ben Azaryah rules - that someone who ...

1. ... enters a room that contains a Bayis ha'Menuga, or who ...

2. ... climbs a tree whose branches extend over a Bayis ha'Menuga is Tahor (just like one who enters the attic above it).

(b)R. Elazar disagrees. He considers the person Tamei - because if one stone from a Bayis ha'Menuga is Metamei be'Ohel, how much so the entire room.

(c)The Halachah is - Like R. Elazar (see Tos. Yom-Tov).

11)

(a)If a Metzora is standing (or sitting) under a tree when a Tahor person passes under the branches, the Mishnah rules - that the latter is Tahor, but he is Tamei if he is standing still and it is the Metzora who walks past.

(b)If, in the latter case, the Metzora puts the stone down (see Tos. Yom-Tov) - the Tahor person becomes Tamei.

(c)And when the Tana says 've'Chein be'Even ha'Menuga'as, he means - that the same will apply if Reuven is carrying an Even Menuga'as under the tree where Shimon is standing (i.e. Shimon remains Tahor), and then stops (he becomes Tamei).

(d)The source for this ruling is - the Pasuk "mi'Chutz la'Machaneh Moshavo", which indicates that the location must become the Metzora's, which we interpret to mean that he must be static (see Tos. Yom-Tov).

12)

(a)A ...

1. ... Tahor who sticks his head into a Bayis Tamei remains Tahor until most of his body enters too (see Tos. Yom-Tov), and the same applies to a ...

2. ... Tahor room into which a Tamei person sticks his head.

(b)

1. Three Etzba'os (fingerbreadths) of a Tahor garment need to enter a Tamei room for the garment to become Tamei, whereas ...

2. ... if even a k'Zayis of a Tamei garment enters a Tahor room (see Tos. Yom-Tov) for the room to become Tamei ...

(c)... and the same will apply if instead of a woolen garment entering a room, it is a leather one or just Sh'si or Areiv.

13)

(a)We learn from the Pasuk ...

1. ... "u'le'Tzara'as ha'Beged ve'la'Bayis" - that a Talis Menuga'as is Metamei whoever enters the room where it is just like a Bayis Menuga (see Tos. Yom-Tov DH 'u'Temei'ah she'Hichnis').

2. ... "Zos Toras Nega Tzara'as, Beged ha'Tzemer" - that a leather garment, Sh'si or Areiv have the same Din as a woolen one in this regard (see Tos. Yom-Tov Ibid.).

(b)The reason that the Shi'ur for a Tamei garment that enters a room to be Metamei the room three a k'Zayis (and not three Etzba'os) is - because Tzara'as is compared to a Meis (which is Metamei bi'k'Zayis).

14)

(a)Someone who enters a Tamei room become Tamei - the moment he enters it, as do ...

(b)... the clothes, shoes or rings that he is ...

1. ... holding in his hand, but not those that he is ...

2. ... wearing - which only become Tamei if he remains in the room as long as it takes to eat a specified amount that we will define shortly ...

(c)... because whereas the things that he is holding are Tamei on account of the room, those that he is wearing are Tamei through him.

15)

(a)We learn from the Pasuk "ve'ha'Ba el ha'Bayis, Yitma" - the former Halachah (i.e. that he and whatever he is holding are Tamei immediately).

(b)Bearing in mind that the Torah writes "ve'ha'Ochel ba'Bayis" and "ve'ha'Shochev ba'Babayis", we learn from the second "Yechabes Begadav", which otherwise appears superfluous - that the person is Tamei even if he does not actually eat or lie in the house.

(c)Regarding the latter ruling, the Torah writes ...

1. ... "ve'ha'Ocheil ... " - to teach us that what is wearing become Tamei only if he remains in the house the time it takes to eat.

2. ... "ve'ha'Shochev ... " - to teach us that the eating would be done in a state of reclining (see Tos. Yom-Tov).

16)

(a)We learn from Halachah le'Moshe mi'Sinai, that the Shi'ur Achilah the Torah is referring to is K'dei Achilas P'ras - which is the equivalent of half the loaf that is required for Eruv Techumin.

(b)According to Rashi, this is four egg-volumes, according to the Rambam - three (see Tos. Yom-Tov).

(c)The bread would have to be eaten - together with condiments (and in a reclining position, as we already explained).

(d)All this results in a reduced time period, since these specifications cause a person to eat quicker (see Tos. Yom-Tov).

17)

(a)If someone enters a Tamei room and stands there with his hand stretched outside ...

1. ... wearing a ring, he becomes Tamei - as soon as he has been in the room for the time it takes to eat a K'dei Achilas P'ras.

2. ... holding a ring - they are Tamei immediately (as we learn in the Tosefta).

(b)In the reverse case (where he is standing outside the Tamei room, but his hand which is holding a ring is stretched inside), R. Yehudah rules that the ring is Tamei immediately. According to the Chachamim - his body (see Tos. Yom-Tov) is Tamei only after he has been in the room for the time it takes to eat a K'dei Achilas P'ras.

(c)To prove their ruling, the Chachamim cite'Kal va'Chomer' - if when his body becomes Tamei, what he is wearing becomes Tamei only after he has been in the room a Shi'ur 'K'dei Achilas P'ras', how much more so where it does not!

(d)R. Yehudah counters that we find that a Tamei saves where a Tahor does not - in the case of a Nochri and an animal standing in a Bayis ha'Menuga, whose clothes and rings (that they are wearing) are Tamei immediately, even thoufh they themselves are not subject to Tum'ah, as opposed to a Yisrael, whose clothes and rings (that he is wearing) do not become Tamei unril the Shi'ur 'K'dei Achilas P'ras', even though he becomes Tamei immediately.

(e)The Halachah - is like the Chachamim.

18)

(a)According to the Tana Kama, the Keilim in a room Tamei if a Metzora enters it - up until the ceiling.

(b)R. Shimon's source for confining the previous ruling to Keilim up to the height of four Amos is - that, in his opinion, above four Amos is considered a different domain (three equivalent to an average man's height, plus one to stretch his arms).

(c)The Halachah - is like the Chachamim.

19)

(a)R. Yehudah qualifies the Tana Kama's statement 'Keilim Miyad Temei'im' (see Tos. Yom-Tov). He agrees with him as long as the Metzora entered the room with the owner's permission.

(b)If the Metzora entered without permission, he gives a Shi'ur of the time it takes to light a candle - because we assume that the owner allowed him to remain in his house only because that is what he was busy doing. Once that time period passes however, and he has not objected, it is clear that he does not object to him remaining.

(c)The basis for this distinction is - the fact that the location only becomes Tamei if it is considered 'the Metzora's place', which is only possible when he has the owner's consent.

20)

(a)To enable a Metzora to go to Shul without contaminating the other Mispalelim - one must build a Mechitzah.

(b)The Mechitzah's ...

1. ... height must be - ten Tefachim (like a regular Mechitzah).

2. ... length must be - four Amos.

(c)This might correspond to the four Amos of Tefilah - with reference to the four Amos of someone who is Davening within which one is forbidden to sit (see Tos. Yom-Tov).

(d)Alternatively, this Shi'ur corresponds to - the four Amos that a person takes up when he lies down and stretches, and which Chazal therefore allotted to him (regarding Kinyanim).

21)

(a)Assuming that there is only one entrance, how the Metzora avoids contaminating all the other Mispalelim when he enters and when he leaves the Shul - by entering first and leaving last.

(b)He is not simply given instructions to leave Shul without stopping - for fear that he might nevertheless stand still.

22)

(a)Whatever saves from Tum'ah in an Ohel ha'Meis Tzamid Pasil in an Ohel ha'Meis - such as an earthenware vessel, saves from Tum'ah in a Beis ha'Menuga.

(b)According to R. Meir, whatever saves from Tum'ah when it is covered in an Ohel ha'Meis - such as a pit or an enclosure, also saves from Tum'ah when it is covered in a Beis ha'Menuga.

(c)R. Yossi says - that in a Beis ha'Menuga it saves even if it remains open (see Tos. Yom-Tov).

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