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.