1)

(a)The Mishnah discusses a plank that covers the top of a new oven - one that has not yet been heated after its completion, and there is a k'Zayis Meis underneath it and Keilim on top of it, or vice-versa.

(b)The plank - covers the oven and protrudes from the top to cover either the Meis or the Keilim.

(c)What makes it different than an old one is the fact that - it is not yet classified as a K'li (see also Tos. Yom-Tov).

(d)The Mishnah therefore rules that - the Keilim are Tahor.

2)

(a)In the same case, but where the oven is an old one, the Tana Kama declares the oven Tamei - and how much more so the Keilim underneath the plank (if the Tum'ah is on top of it), and on top of it (if the Tum'ah is underneath it).

(b)The reason for this ruling is - because the oven is s K'li, and Keilim serve as an Ohel to transmit Tum'ah, but not to save from Tum'ah.

(c)R. Yochanan ben Nuri however - declares the oven Tahor (but not the Keilim underneath the plank or on top of it [see Tos. Yom-Tov]).

(d)In a case where the plank covers two ovens and there are Keilim placed on the ground in between them - the same Tana'im issue exactly the same rulings (both regarding the ovens and the Keilim in between them [see Tos. Yom-Tov).

3)

(a)Now the Tana discusses a similar case, only this time it is a S'ridah - a net cover (see Tos. Yom-Tov). that covers the top of an oven and extends beyond it.

(b)The S'ridah must also be Chalakah - which means that it does not have a rim (see Tos. Yom-Tov)

4)

(a)The Mishnah also requires the S'ridah to be firmly attached to the oven for the Keilim inside the oven to remain Tahor (should the Tum'ah be perched on top of the plank above them).

(b)Assuming that the Tum'ah is underneath the plank or on top of it, at the side of the oven, the Tana rules that the Keilim that are correspondingly ...

1. ... directly on top or underneath the plank (but not inside the oven) - are Tamei; how much more so the Keilim that are ...

2. ... on top or underneath the plank, on the far side of the oven.

(c)Whereas if the Tum'ah is on top of the plank above the air-space of the oven (see Tos. Yom-Tov) - he declares all the Keilim Tahor, except for those that are directly above it (right up to the sky).

5)

(a)In a case where the plank covers the oven and protrudes from it at two opposite ends (e.g. east and west), but not on the other two sides, and the Tum'ah is underneath one end of the plank - the Tana Kama declares the Keilim underneath the other end, Tahor (see Tiferes Yisrael).

(b)R. Yossi - declares them Tamei (see Tiferes Yisrael).

(c)And when the Tana says ha'B'tach (or Avtach [a bath that is actually carved into the building] see also Tos. Yom-Tov) Eino Meivi es ha'Tum'ah, he means that - in similar circumstances, the plank that covers the B'tach at two opposite ends does not transmit Tum'ah to the Keilim underneath the other end, either.

6)

(a)In a case where it is not a plank, but a ledge that runs across the top of the bath, R. Eliezer issues the same ruling as the previous one. R. Yehoshua rules - Tamei ...

(b)... because we see B'tach as if it did not exist (it is not Chotzetz like the plank is [see Tos. Yom-Tov & Tiferes Yisrael]).

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

7)

(a)Sandal shel Arisah is - a sort of shoe that is fitted on to each leg of a cot.

(b)Besides being decorative - it might also serve to protect the legs from the earth, which will otherwise cause them to rot.

(c)The Mishnah rules that in a case where the floor on which the cot is standing breaks, and the Sandal is actually visible from the room below, assuming that the hole measures ...

1. ... a Pose'ach Tefach - everything in the attic becomes Tamei for seven days (as if the Tum'ah was there).

2. ... less than a Pose'ach Tefach, the Tana rules Monin bo ke'Derech she'Monin ba'Meis, by which he means that - the Sandal and the cot become Tamei for seven days (like Keilim that touch Keilim [that are touching a Meis], as we learned in the first Perek), whereas the baby who is lying in the cot is Tamei until nightfall, whereas everything else in the attic is Tahor (see Tos. Yom-Tov).

8)

(a)The Mishnah now discusses beams of a ceiling of a room and of the attic that are not cemented (see Tos. Yom-Tov), and that are exactly in line with one another. To enable the Keilim above or below them to remain Tahor, the beams must be - at least a Tefach wide.

(b)The Tana rules that, assuming the k'Zayis Meis is found ...

1. ... underneath one of the bottom beams - whatever is directly underneath it (exclusively) is Tamei.

2. ... between one of the bottom beams and the one above it - whatever is directly in between them is Tamei.

3. ... on top of one of the top beams - then whatever is directly above it (up to the sky) is Tamei.

(c)If the lower beams are directly in line with the spaces in between the upper ones (see Tos. Yom-Tov), and the Tum'ah is ...

1. ... underneath one of them - then all the Keilim in the room are Tamei.

2. ... on top of it - whatever is in line with it up to the sky is Tamei.

9)

(a)Now the Mishnah discusses a beam that is in the open and that stretches from wall to wall, underneath one end of which there is a k'Zayis Meis, and underneath the other, Keilim. Assuming that the beam measures a Tefach in width (see Tos. Yom-Tov), the status of ...

1. ... the Keilim at the other end is - Tamei, whereas

2. ... Keilim that are perched on top of the beam - remain Tahor.

(b)If however, the beam is less than a Tefach wide - then we will apply the principle Tum'ah Boka'as ve'Olah, in which case Keilim that are not in line with the Tum'ah remain Tahor.

10)

(a)The above speaks with regard to a square beam. If it is round - then the former Din will apply provided the circumference of the beam is at least three Tefachim ...

(b)... based on the principle that Whatever has a diameter of one Tefach has a circumference of three Tefachim ...

(c)... as we learn from the Yam shel Shlomoh [the large Mikvah in the Azarah of the Beis Hamikdash, that was built by Shlomoh Hamelech to enable all the Kohanim to Tovel at the same time] see Tos. Yom-Tov]).

11)

(a)The minimum circumference required by the Tama of a round Amud lying in the open to be, for Keilim that are underneath it to become Tamei is - twenty-four Tefachim (four Amos) ...

(b)... because that will allow a cubic Tefach to fit into the space between the widest part of the Amud and the ground.

(c)The basis of this ruling is a combination of two principles - 1. The square surrounding a circle is a quarter more than the circle (as a result of which each side of the square will be ten Tefachim), and 2. The diagonal of an equilateral triangle is one and two/fifths times each of the other two sides (in which case the distance from the point where the diameter touches the circumference of the Amud and the far corner of the square will be one and three fifths of a Tefach. This means that the square is fractionally more than the required minimum cubic Tefach (as the diagonal of a square of a Tefach is one and two-fifth Tefachim) ...

(d)... which does not matter, either because, seeing as the discrepancy is so small, the Tana prefers to give a round figure (le'Chumra), or - because the second principle is anyway not completely accurate (but is slightly more [see Tos. Yom-Tov]).

12)

(a)The Keilim will become Tamei even if they are lying close to the part of the Amud that is touching the ground, which measures less than a cubic Tefach - because of the Din of Shipu'ei Ohalim (as we learned in Perek 7, Mishnah 3).

(b)If the entire space is less than a cubic Tefach - we will apply the principle Tum'ah Boka'as ve'Olah. to render Tamei Keilim that are directly above it (exclusively).

13)

(a)If a k'Zayis Meis is stuck to the outer section of the threshold (underneath the awning), R. Eliezer declares the house Tamei. R. Yehoshua - declares it Tahor ...

(b)... because he does not consider the outer part of the threshold to be part of the house, whereas R. Eliezer does (see Tos. Yom-Tov).

(c)In a case where the Tum'ah is lying on the ground below the threshold - the house is Tamei only if that spot is located within the inner half of the threshold (see Tos. Yom-Tov).

14)

(a)The Tana Kama equates the Din of where the Tum'ah is stuck to the outside of the lintel, with R. Eliezer's ruling in the previous case (where it is stuck to the threshold). R. Yossi - declares it Tahor ...

(b)... because he does not consider the outside of the lintel to be Tamei, whereas the Tana Kama does (see Tos. Yom-Tov).

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

15)

(a)If the k'Zayis Meis is lying inside the house, somebody who touches the lintel - will become Tamei.

(b)According to R. Eliezer, the same will apply to someone who touches the threshold. R. Yehoshua agrees - provided he touches the top Tefach, but if he touches the lintel anywhere below that, he will remain Tahor.

(c)R. Yehoshua is more stringent here than in the earlier case, where the Tum'ah is stuck to the threshold - because in this case, the Tum'ah is bound to cross the threshold as it is taken out of the house.