Ohalot, Chapter Ten, Mishnah Two
1) If the hatchway does not have an opening of a square handbreadth:
2) If there is uncleanness in the house, what is directly [below] the hatchway remains clean.
3) If the uncleanness is directly [below] the hatchway, the house remains clean.
4) When the uncleanness is in the house, if he placed his leg above [the hatchway], he remains clean.
5) [When] the uncleanness is directly [below] the hatchway, if he placed his leg above it,
a) Rabbi Meir declares [him] unclean,
b) But the sages say: if the uncleanness was [in position] before his leg, he becomes unclean, but if his leg was [in position] before the uncleanness, he remains clean.
6) Rabbi Shimon says: [in the case where] two [men’s] legs, one above the other, were [in position] before the uncleanness, if the first person withdrew his leg and the other person’s leg was still there, [the second] remains clean, because the first person’s leg was [in position] before the uncleanness.
Section one: Our mishnah discusses a case where the hatchway is less than a handbreadth square.
Section two: Even though the hatchway is less than one handbreadth, we do not consider the house to be closed and for the tent and the hatchway to be one ohel. Rather the same rule that applied in yesterday’s mishnah applies herewhat is below the hatchway remains clean.
Section three: Again, although the hatchway is less than one handbreadth, we don’t consider the house to be one ohel. If the impurity is below the hatchway, what is in the house remains clean.
Section four: The person who put his leg above the hatchway remains pure because the impurity is trapped in the ohel that he created below. This is because the opening is less than one handbreadth. However, since the house and hatchway are one tent, whatever is found below is impure.
Section five: According to Rabbi Meir since the person overshadowed the source of corpse impurity, he is impure.
The sages say it depends on what comes first. If the source of impurity is there first then he is impure because he put his leg over the hatchway before he made the house into one ohel. However, if his leg was there first, then when the impurity got there, the house was already one ohel and impurity does not escape from an ohel through a hole of less than one handbreadth.
Section six: Rabbi Shimon complicates the above scenario a little bit. The sages said that if the impurity was there before the person’s leg was there, then the person is impure. Here, two people’s legs were there, one on top of the other. When the first person removed his leg, the second person’s leg now went over impurity that was there first. Nevertheless, since the house was an ohel by virtue of the first person’s leg, the second person is pure.