1)

(a)A person who touches a Meis is Tamei for seven days - based on the Pasuk in Chukas "ha'Noge'a be'Meis ... ve'Tamei Shiv'as Yamim" (which teaches us that he becomes an Av ha'Tum'ah).

(b)When the Mishnah says 'Shenayim Temei'in ba'Meis, Echad Tamei Tum'as Shiv'ah, ve'Echad Tamei Tum'as Erev', it means that - if Shimon touches Reuven who touched a Meis, then Reuven is Tamei for seven days, but Shimon for only one (see Tos. Yom-Tov).

(c)The Chachamim declared even Shimon Tamei for seven days however - if he touches Reuven whilst he (Reuven) is still touching the Meis.

2)

(a)When the Mishnah says 'Sheloshah Temei'in ba'Meis, Shenayim Temei'in Tum'as Shiv'ah, ve'Echad Tamei Tum'as Erev' it means that ...

1. ... if Keilim touch Keilim which touched a Meis, they are all Tamei for seven days, whereas ...

2. ... if either Adam or Keilim touched the second set of Keilim, they are Tamei for only one day.

(b)The source for Keilim becoming Avi Avos ha'Tum'ah (like the Meis itself) is - the Pasuk there "ba'Chalal Cherev" (from which Chazal derive 'Cherev, Harei hu ke'Chalal', with reference to any vessels (known as K'lei Shetef [other than earthenware ones] see Tos. Yom-Tov).

3)

(a)The Mishnah concludes the sequence with 'Arba'ah ... , Sheloshah Temei'in Tum'as Shiv'ah, ve'Echad Tum'as Erev' - where Adam touched Keilim which touched the Meis, and either Adam or Keilim touched them.

(b)We learn from the Pasuk "ve'Chibastem Bigdeichem ba'Yom ha'Shevi'i" that - whenever Adam is Tamei for seven days, Keilim which touch him are Tamei for seven days too (as in the current case).

(c)The Mishnah did not present the case of Sheloshah where Keilim touched Adam, who touched a Meis, and either Adam or Keilim touched the Keilim - because the Chidush that we just cited (that whenever Adam is Tamei for seven days, Keilim which touch him are Tamei for seven days too), we know from the fourth case, as we just explained (even where Adam only touched Keilim which touched a Meis, how much more so where he touched the Meis itself).

4)

(a)R. Akiva adds a case where there are five (the first four are Tamei Shiv'ah, and the fifth, Tum'as Erev) - where Keilim touch Adam who touches a spit-rod which is stuck in an Ohel ha'Meis (Shevi'i) and either Adam or Keilim touch them (Tum'as Erev).

(b)The Chachamim reject R. Akiva's addition on the grounds that 'Ein ha'Ohel Mischashev', which may mean that the Ohel is not Metamei the spit-rod. Alternatively, it might mean that - it is not counted because the same sequence would take effect if the spit-rod merely touched the Ohel from the outside.

5)

(a)The Chumra the Mishnah presents of ...

1. ... Keilim over Adam is that - if Keilim touch Keilim, which touched Keilim which touched a Meis, they are all Tamei, which would not be the case if three b'nei Adam replaced the Keilim.

2. ... Adam over Keilim is that - as long as there is one Adam in the first three, then the fourth one is Tamei too (otherwise the maximum is three [see Tos. Yom-Tov]).

6)

(a)The Tana now lists the Chumros of Adam that become Tamei via a Zav over Keilim, and vice-versa. The Chumra of ...

1. ... Adam over Begadim in this regard is that - Adam who touches a Zav renders his Begadim Tamei (which Begadim do not).

2. ... Begadim over Adam is that - Begadim that carry a Zav (Mishkav or Moshav [see also Tos. Yom-Tov]) render a person Tamei (which a person does not).

(b)In the former case, even if Adam touches the person whilst he is still touching the Zav - he nevertheless does not render him Tamei (because he is a Rishon, and a Rishon is not Metamei Adam (see Tos. Yom-Tov).

7)

(a)The Mishnah learns from the Pasuk "Kol ha'Noge'a be'Meis be'Nefesh ha'Adam asher Yamus" that - a person is not Metamei until he is actually dead (see Tos. Yom-Tov).

(b)This precludes a Meguyad - somebody who is cut-up, and a Goseis (a person on his death-bed).

(c)The Tana adds that the latter are 'Zokek le'Yibum u'Poter min ha'Yibum; Ma'achil bi'Terumah u'Posel bi'Terumah'.

1. 'Zokek le'Yibum' means that his wife is forbidden to marry until her husband actually dies, and 'Poter min ha'Yibum' that - if the deceased husband leaves behind a child who is Meguyad or Goseis, his wife is Patur from Yibum.

2. 'Ma'achil bi'Terumah' means that if his deceased father was a Kohen, the child he leaves behind enables his mother who is a bas Yisrael, to continue eating Terumah, and 'Posel bi'Terumah' that - if his deceased father was a Yisrael, then the child disqualifies his bas Yisrael mother from eating Terumah.

8)

(a)The Mishnah rules that an animal ...

1. ... that is a Goseis - is not Metamei Tum'as Neveilah until it actually dies.

2. ... whose head has been severed (see Tos. Yom-Tov) but that is still Mefarcheses (convulsing) - is Metamei ... .

(b)... because, just like a lizard's tail, it convulses even though it is actually dead.

9)

(a)The Mishnah discusses the required size for an Eiver (a limb) - containing flesh, nerves (sinews) and bones, to be Tamei Neveilah.

(b)For an Eiver to be Metamei, there is no minimum size, either for an Eiver min ...

1. ... ha'Meis, or for an Eiver min ...

2. ... ha'Chai.

(c)The Tana cites less than a k'Zayis of Meis, and less than the Shi'ur of Neveilah and of a Sheretz. The Shi'ur he cites for ...

1. ... Neveilah is - a k'Zayis.

2. ... Sheretz is - k'Adashah.

10)

(a)Beginning with the feet, the Mishnah lists the 248 limbs on a man's body. The Tana arrives at 30 in one foot - by counting six in each toe.

(b)The ...

1. ... ankle (Karsul [see Tos. Yom-Tov]) comprises 10 limbs, the calf two.

2. ... knee comprises 5 limbs, the thigh one.

(c)There are 3 limbs in one Katlis - the limb that restss atop the thigh and 11 ribs on one side of the spinal cord.

11)

(a)The Mishnah lists - 30 limbs in a man's hand ...

(b)... six in each finger.

(c)He lists 2 limbs in a man's lower-arm ...

1. ... 2 in his elbow and ...

2. ... 1 in his upper-arm.

(d)The Tana lists 4 limbs in a man's shoulder. He doubles the current total of 101 to 202 - because each of the above is confined to one side of the body, and there are the equivalent amount of limbs on the other side.

12)

(a)The Mishnah lists - eighteen vertebrae in the spinal column.

(b)Finally, the Tana lists 9 limbs in the head, and the limbs in the neck, the chest and the private parts in a regressive order - 8 in the neck, 6 in the chest and 5 in the private parts.

(c)Each of the above-mentioned limbs is Metamei - be'Maga, be'Masa (see Tos. Yom-Tov) and be'Ohel.

13)

(a)If a limb does not contain a k'Zayis (Tos. Yom-Tov) Basar - it is Metamei be'Maga and be'Masa, but not be'Ohel.

(b)We learn from the Pasuk ...

1. ... "Adam ki Yamus ba'Ohel" that - a complete corpse is Metamei be'Ohel.

2. ... "be'Etzem Adam" that - a bone is Metamei be'Ohel as long as, like Adam, it contains flesh and nerves/sinews as well.