There are ten [cases] of houses. If it dulls during the first [week] or goes away, he scrapes it off and it is pure. If it dulls during the second [week] or goes away, he scrapes it off and it requires [sacrificial] birds. If it spreads in the first [week], he removes, scrapes and plasters and gives it a week. If it returns, [the house] must be destroyed. If it does not return, it requires birds. If it stood [unchanged] after the first [week] and spread during the second [week], he removes, scrapes and plasters, and gives it a week. If it returned, the house must be destroyed. If it does not return, it requires birds. If it stood [unchanged] after this [first] and this [second week], he removes, scrapes, and plasters, and gives it a week. If it returns, the house must be destroyed. If it does not return, it requires birds. If before he purified it with birds the Nega [diseased patch on skin, clothes, or houses that creates impurity] reappeared, it must be destroyed. Once it has been purified with birds, if the Nega reappears, it should be examined as if in the beginning [of the Nega].

A cornerstone, when he removes it, is removed in its entirety, but when he destroys [the house], he destroys what belongs to him but leaves what belongs to his neighbor. We find a stringency in the case of removal beyond that of demolition. Rabbi Elazar says, a house built with a cross-beam and a king-beam, if it appeared on the cross-beam he must remove it all, if it appeared on the king-beam, he removes what belongs to him but leaves what belongs to his neighbor.

A house upon which a Nega appeared that had an attic on top of it, the beams are considered part of the attic. If it appeared in the attic, the beams are considered part of the house. If there was no attic on top of it, its stones, wood and dirt are destroyed with it, but it saves the frames and the window lattices. Rabbi Yehuda says the frame built on top of it is destroyed with it. Its stones, wood, and dirt, make it impure with [the size of] an olive. Rabbi Elazar Chisma says, in whatever size they are.

A quarantined house causes impurity from its inside, and a [house] designated [to be destroyed] from its inside and from its outside. Both this and that [types of house] make one impure by entering it.

One who builds a pure house [with bricks] from a quarantined house, and the Nega returned to the house, he removes those stones. If it returned to the stones, the first house should be destroyed and the new stones should serve as indicators for the second house.

A house that extends over a house with a Nega, and similarly a tree that extends over a house with a Nega, one who enters the outer one is pure, says Rabbi Elazar ben Azariah. Rabbi Elazar said, if one of its stones causes one to become impure by entering, should not [the whole house] itself make one impure by entering?!

If an impure person is standing under a tree and a pure person passes [under that tree], he becomes impure. If a pure person is standing under a tree and an impure person passes [under the tree], he remains pure, but if he [the impure person] stood [under the tree], he would become impure. Similarly in the case of a stone with a Nega, [if it passes under] he remains pure, but if he laid it down, he would become impure.

A pure person who extended his head and most of his body into an impure house becomes impure. An impure person who extends his head and most of his body into a pure house makes it [the house] impure. A pure cloak of which a three-by-three [finger-length] piece entered an impure house becomes impure. [If it was] an impure [cloak], if he extended even the volume of an olive [of it] into a pure house, it makes [the house] impure.

One who enters a house with a Nega and has clothing on his shoulders and his sandals and rings are in his hands, he and all of them become impure immediately. If he was wearing his clothes and his sandals were on his feet and his rings were in his hands, he becomes impure immediately, and they are pure until he stays there long enough to eat half a loaf of bread, wheat bread and not barley bread, while leaning and eating with a condiment.

If he was standing inside and he extended his hand outside and his rings were in his hands, if he remained there long enough to eat half a loaf of bread, they are impure. If he was standing outside and extended his hand inside and his rings were in his hands, Rabbi Yehuda declares him impure immediately but the Sages say, until he remains long enough to eat half a loaf of bread. They said to Rabbi Yehuda, "If when his entire body is impure, things that are on him only become impure if he remains long enough to eat half a loaf of bread, when his whole body is not impure should not what is on him certainly not become impure until he remains long enough to eat half a loaf?"

A leper who enters a house, all of the vessels within it become impure even up to the beams. Rabbi Shimon says, [only] up to four cubits. The vessels become impure immediately. Rabbi Yehuda says, not until he stays long enough to light a candle.

If he enters a synagogue, they make for him a wall ten Tefachim [specific unit of length] high by four Tefachim wide. He enters first and exits last. Anything that is saved by a seal in the tent of a dead person is saved by a seal in a house with a Nega. Whatever is saved by being covered in the tent of a dead person is saved by being covered in a house with a Nega, says Rabbi Meir. Rabbi Yossi says, Anything that is saved by a seal in the tent of a dead person is saved by being covered in a house with a Nega. Whatever is saved by being covered in the tent of a dead person, even if it is uncovered in a house with a Nega, remains pure.