Comentário sobre Ohalot 15:8

חצר הקבר – he courtyard that surrounds from its four directions four caves of graves.

[With regard to] the courtyard of a tomb: A person standing in it remains clean as long as there is a space of four cubits square, according to the words of Bet Shammai. Bet Hillel says: four handbreadths. The courtyard described here is at the entrance to a tomb. According to Bet Shammai, the courtyard must be at least four cubits square to be considered its own space. If it is this size, a person standing there will not be defiled by the tomb because he is not considered to be in the "tomb". Bet Hillel provides a smaller measure. If the courtyard is at least four handbreadths square, it is its own space.

טהור עד שיהא בה ארבע אמות – all the while that there are four cubits the person who stands in its midst is ritually pure. But less than four cubits, the person who stands in its midst is impure, but if there aren’t there other than three caves from three directions and the fourth direction of the courtyard is open to the airspace of the world, even if he isn’t is not distanced from the opening of the cave other than whatever the amount, he is pure, as long as he doesn’t touch the lintel of the opening of the cave. And these words [apply] when the courtyard of the grave is marked with a partition, but for a mere corpse [it takes only] four cubits for defilement.

[With regard to] a roof beam which had been used as a covering stone for a tomb, whether it is standing upright or lying on its side, nothing becomes unclean except what [touches] opposite the opening of the grave. A roof beam was used to close up a burial grave. Typically, this was done with a stone. A person who touches the part of the beam that is opposite the stone is impure; but if he touches it elsewhere, he is pure.

גולל לקבר – a covering on the opening of the burial cave.

If the end [of the beam] were made the covering stone of a grave, only [that part] up to four handbreadths [from the grave] becomes unclean. In this case he puts the end of the beam up against the cave, with the beam extending out from the grave. The first four handbreadths of the beam are considered to be covering the grave and are impure and defile one who touches them. After that, the beam is pure.

אלא כנגד הפתח (only the part directly opposite the opening) – of the burial crave. But a person who touches the end that is placed outside of the grave, is ritually pure.

[This applies] when [the beam] is going to be cut. Rabbi Judah says: all the beam is connected. The above is true if he intends to cut off the beam and leave only the four handbreadths that cover the grave. If he intends to leave the entire beam there, it all defiles. Rabbi Judah rules more strictly. The whole beam is connected to the part that covers the grave and therefore, even if he intends to cut it off, it is still impure.

עשה ראשה גולל לקבר – and behold it stands over the burial cave like a tree. A person who comes in contact with it at four handbreadths near the burial cave is impure because of the stone placed on top of a burial cave/top stone, but from four [handbreadths] and above, he is pure.

בזמן שהוא עתיד לגוד – to cut it off. And even though he did not cut it yet. [The word] לגוד is like (Daniel 4:20): “[The holy Watcher whom the king saw descend from heaven and say,] Hew down the tree [and destroy it].”

כולו חיבור – all he while that he did not cut it, and even though he will ultimately cut it down. But the Halakha is not according to Rabbi Yehuda.