Ohalot, Chapter Fourteen, Mishnah One
Chapter fourteen deals with various projections that jut out above the entrance to a house and with whether they form an ohel to allow the impurity to enter the house.
1) A projection brings uncleanness, whatever width it may be;
2) But a balcony or rounded balcony when they are one handbreadth wide.
3) What is a projection? That [projection] whose surface slopes downwards,
4) And a balcony’s surface slopes upwards.
5) In what [circumstances] did they say that a projection brings uncleanness whatever width it may be?
a) With regard to a projection which is three rows of stones, or twelve handbreadths, above the doorway.
b) When higher than that, it brings uncleanness only if it is one handbreadth wide.
6) Cornices and carvings bring uncleanness when they are one handbreadth wide.
Sections one and three: As will be explained in section three, the “projection” referred to here seems to be some sort of canopy that slopes downward and is used to protect the entrance to the house from rain and sun. Since this canopy is really part of the house, it joins the house to bring impurity in. Therefore, it itself does not need to be a handbreadth, the generally required size of an ohel. If a source of corpse impurity is found under this projection, the house will be impure.
Sections two and four: In contrast, a balcony’s surface slopes upward so that it can be used by those living on the upper floor. It does not join the entrance to the house below to bring impurity into the house unless it is itself the size of an ohel, meaning one handbreadth.
Section five: For a projection to join with the opening of a house to allow impurity into the house it cannot be more than twelve handbreadths (equivalent to three rows of stones) above the doorway. Up to such a height and the canopy-projection can conceivably protect the entrance. But above this height it will need to be a handbreadth in order to form a tent to bring impurity in.
Section six: Anything made for aesthetic purposes was not designed to protect the entrance. Therefore, it does not join with the entrance