Comentário sobre Ohalot 4:1

מגדל העומד באויר (a tower/cupboard standing isolated) – a wooden turret that has walls but the walls themselves have a cavity in their thickness, such as perforated holes that are open to the inside and the outside but they lack an opening of a handbreadth, and it is customary to hide there needles and hooks/curved pins and small vessels.

A cupboard standing in the open air: If there is uncleanness within it, vessels in the [niches in the] thickness [of its walls] remain clean. If there is uncleanness in [the niches in] its thickness, vessels inside [the cupboard] remain clean. Rabbi Yose says: half and half.
When it is standing inside a house: If there is uncleanness inside [the cupboard], the house is unclean; If there is uncleanness in the house that which is within [the cupboard] remains clean, for the manner of uncleanness is to go out and not to go in.
Vessels which are between [the cupboard] and the ground, or between it and the wall, or between it and the roof-beams: If there is a space of one cubic handbreadth there, they become unclean. If not they remain clean.
If there is uncleanness there, the house becomes unclean.
Section one: The cupboard in our mishnah is large enough such that it doesn't receive impurity in itself. The cupboard is outside in the open air and not in the house.
If there is a source of impurity in the cupboard, and there are vessels in niches in the thickness of its walls, these vessels remain pure. These niches are not considered to be in the space of the cupboard. Similarly, if there is a source of impurity within the niches, the vessels inside the cupboard are pure.
Rabbi Yose disagrees. He divides these niches in half and says that the inner half is considered to be like the cupboard and the outer half is considered to be like the space outside the cupboard.
Section two: If the cupboard is within a house, then the impurity can escape the cupboard and go into the house (even if the cupboard is locked), but impurity from the house does not enter the cupboard (as long as the cupboard is closed). This is because of the rule that impurity escapes but does not enter.
Section three: This section describes a situation in which vessels are found in between the cupboard and the walls, floor or roof of the house, and there is a source of impurity in the house or in the cupboard. If there is a space that is at least 1 x 1 x 1 handbreadths, then the impurity goes in there through the fact that the house acts as an ohel. But if the space is smaller, the impurity does not enter, for impurity does not enter such small spaces.
However, if there is impurity in that space, then the house is impure because the impurity is inside the house. The cupboard is impure because impurity goes out but does not enter.

שהוא עומד באויר—underneath the airspace of the sky, such as that it stands in the courtyard.

טומאה בתוכו – in the cavity of the turret itself.

כלים שבעוביו – in the thickness of the cavity of the walls.

מחצה למחצה – from its half of the thickness of the cupboard/turret and towards the inside is like the inside, from its half [of the thickness] towards the outside is like the outside. Whether the defilement is in the turret/cupboard and the vessels are in its thickness, or whether the defilement is in its thickness and the vessels are in the turret/cupboard. But the Halakha is not according to Rabbi Yossi.

טומאה בתוכו – within the turret/cupboard.

הבית טמא – even though that its doors are sealed. As it (i.e., the Mishnah) explains the reason that the manner of the defilement/uncleanness is to depart from there to the house.

טומאה בבית מה שבתוך המגדל – this is with its doors sealed. For if they are opened, it is no worse than a window that is between the two houses. For the reason that what is within the turret/cupboard is ritually pure, is that there is no path for the defilement that is in the house to enter into the turret/cupboard.

אם יש שם פותח טפח – between the rims of the turret/cupboard and the ground or between the wall of the turret/cupboard to the wall or between the roof the turret to the ceiling of the house.

טמאים – on account of the defilement that is in the house. But if there isn’t there [an opening] of a handbreadth, the turret/cupboard is like a לבוד/joined (i.e., that two solid surfaces are considered to be joined if there is a gap less than three handbreadths between them). And the defilement of the house does not enter there.

טומאה שם הבית טמא – if there was defilement between the rims of the turret/cupboard to the ground of the house. Or [there was defilement] between the roof of the turret to the roof of the house or between the walls of the turret to the walls of the house, even though there isn’t between them an opening of a handbreadth. הבית טמא – for the turret/cupboard does not protect regarding the defilement that is below it within the house so that it doesn’t defile all that is in the house.