[The Kohen] does not go into his [own] house to confine, nor [does he stand] inside the house that contains the nega to confine. Rather, he stands next to the entrance of the house that contains the nega and confines, as stated: ‘‘And the Kohen shall leave the house to the entrance of the house, and he shall confine the house for seven days.’’ He returns at the end of the week and examines [the house]. If it spread, ‘‘and the Kohen commands that they remove the stones that have the nega and throw them outside the city to a tamei place. And they shall take other stones to replace the [removed] stones, and he shall take other clay and plaster the house.’’ He does not take stones from this side [of the house] and build them into the other side; nor [does he take] clay from this side and build [it] into the other side, nor [does he take] lime. Two [stones] are not replaced with one [stone], nor one [stone] with two, but two, three, or four [stones] can be replaced with two. From here they said: ‘‘Woe is to the evildoer and woe is to his neighbor.’’ Both [owners] remove [the afflicted stones], scrape [around them], and place the [new] stones. However, he alone brings clay, as it is stated: ‘‘And he shall take other clay and plaster the house.’’ His neighbor does not assist him in the plastering.

[The Kohen] returns at the end of the week to examine [the house]. If [the nega] returned, ‘‘The house is demolished — its stones, its wood, and all the clay of the house — and removed from the city to a tamei place.’’ An adjoining expansion [of] any size is tamei; a distant one must be the size of a gris. The return of a house nega must be two gris.

There are ten houses: [If the nega] turns dull after the first [week] or [it] disappears, it is scraped off and [the house] becomes tahor. [If the nega] turns dull after the second [week] or [it] disappears, it is scraped off, and the house requires taharas hatzipporim. [If the nega] spreads after the first [week], [the owner] removes, scrapes, and plasters, and [the Kohen] gives [the house] a week [of confinement]. [If the nega] returns, [the house] is demolished. [If the nega] does not return, [the house] requires taharas hatzipporim. [If the nega] remains the same after the first [week] and spreads after the second, [the owner] removes, scrapes, and plasters, and [the Kohen] gives [the house] a week [of confinement]. [If the nega] returns, [the house] is demolished. [If the nega] does not return, [the house] requires taharas hatzipporim. [If the nega] remains the same after both [weeks], [the owner] removes, scrapes, and plasters, and [the Kohen] gives [the house] a week [of confinement]. [If the nega] returns, [the house] is demolished. [If the nega] does not return, [the house] requires taharas hatzipporim. If the nega reappears before [the owner] made [the house] tahor with taharas hatzipporim, [the house] is demolished. If [the nega] reappears after [the owner] made [the house] tahor with taharas hatzipporim, [the house] is examined anew.

A cornerstone [which the owner] is required to remove must be completely removed. But when he [is required to] demolish it, he demolishes his [side] and leaves his neighbor’s [side]. This results in a stringency in the removal [of the stones] over the demolition [of the house]. R’ Elazar says: A house built with a main support and smaller materials [where the nega] appears on the main support, [the owner] is required to remove all of it; [where] it appears on the smaller materials, he removes his [side] and leaves his neighbor’s [side].