[If] a person plows over a pit containing corpses, through a pile of bones, through a field in which a grave was lost, through a [field] in which a grave was [subsequently] found, [or] through [a field] that is not his property, or a gentile plows, it does not make a beis hapras — because [the ruling of] beis hapras does not apply to Cutheans.

[If] a beis hapras field is above a tahor field [and] rain washed down [soil] from the beis hapras to the tahor [field], even [if the field was] red and now it turned white, or white and now it turned red, [the beis hapras soil] does not make [the tahor field] in-to a beis hapras.