A field in which a grave was lost can be planted with any seeds, but no trees can be planted, nor can you allow trees to remain except for barren trees that produce no fruit. [The field] spreads tumah through touch, carrying, and ohel.

A wailing field may not be planted with either trees or grains, and its soil is tahor. [Furthermore,] one may make ovens for holy items [from its clay]. Beis Shammai and Beis Hillel agree that we check [for bone fragments] for one making the pesach offering, but we do not check for [one who eats] terumah. And as far as a nazir is concerned, Beis Shammai say: We check it, and Beis Hillel say: We do not check it. How does he check? He brings earth that can be moved and places it inside a sifter with very thin holes and crumbles (any clods) — if there was a bone the size of a barleycorn was found, [the person] becomes tamei.

How do they make a beis hapras tahor? One removes three handbreadths from it or one places three handbreadths on top of it if he removed three handbreadths from one half and placed three handbreadths on top of the other half, it is tahor. R’ Shimon says: Even if he removed a handbreadth and a half or he placed on top of it a handbreadth and a half from a different place, it is tahor. If the beis hapras is paved with stones that [are large enough that they] cannot be moved, it is tahor. R’ Shimon says: Even someone who hoes the beis hapras [makes it] tahor.

Someone who walks through a beis hapras on stones that he does not cause to move, [or] on a person or an animal that are very strong, is tahor. [However, some-one who walks through a beis hapras] on stones that he causes to move, [or] on a person or an animal that are not strong, is tamei. Someone who walks in the land of the nations on mountains or rocks is tamei; in the sea or in silt is tahor. What is silt? Any place to which the sea rises in its fury.