One who plows over a grave, this one makes a Beit Pras [a field in which a grave has been plowed over]. Up until where does he make it? A whole furrow, one hundred cubits long, four Beit Se'ah [a measure of area, equivalent to that area of land large enough to require a Se'ah of seeds to sow it]. Rabbi Yosi says, an area of five. On a downward or upward slope, he places a Rova [specific unit of volume] of vetch on the knee of the plow until the place where three vetches will sprout one next to the other, up until there he makes a Beit Pras. Rabbi Yossi says [this applies] on a downward slope but not an upward slope.

If he was plowing and he hit a rock or a fence or if he shook the plow blade, until that point he makes the Beit Pras. Rabbi Eliezer says a Beit Pras can make a Beit Pras. Rabbi Yehoshua says there are times when it does make one, times when it does not make one. How so? If he plowed half a furrow and then plowed the other half and so too on the sides, this makes a Beit Pras, but if he plowed a whole furrow and then plowed it from there beyond, it does not make a Beit Pras.

One who plows over a pit of bones or a pile of bones, a field in which a grave was lost in it, or in which a grave was found [after plowing], one who plows [a field] that is not his, and similarly a non-Jew who plowed, does not make it into a Beit Pras since there is no Beit Pras for Cuthites.

If the Beit Pras field was above a pure one and rains washed from the Beit Pras to the pure one, even if the soil had been red and turned white or was white and turned red, it is not made into a Beit Pras.

A field in which a grave was lost, and they built a house with an upper story on top of it, if the doorway of the upper story was aligned with the doorway of the house, the upper story is pure, but if not the upper story is impure. Dirt of the Beit Pras and dirt of land outside the land of Israel which came in a vegetable combine [to become impure if their combined size is as large as] the seal of leather sacks says Rabbi Eliezer. But the Sages say [they do not become impure] until there is [the size of] the seal of leather sacks in one place. Rabbi Yehuda says, it once happened that letters came from overseas to the sons of the High Priests with a Se'ah or two Se'ah of seals but they [the Sages] were not concerned about their impurity.