1

Houses with tzara'at blemishes are deemed impure when the blemishes are the length of two grisim. Thus the width of the blemish is approximately the size of a place where six hairs grow on the body and its length is a place for 12 hairs. It must be rectangular. Any blemish on a house smaller than this measure is pure. All of the measures are halachot transmitted to Moses at Sinai.

2

There are three distinguishing marks of impurity for tzara'at in houses: an intense green or intense red appearance and the spreading of the affliction. These are all explicitly mentioned in the Torah.

The two abnormal appearances can be combined with each other. If a blemish spreads to the place immediately adjacent to it, even the slightest spread is considered a sign of impurity. If it spreads to a distant place, the new blemish must be a gris. When a blemish returns after the house is plastered, it must be two grisim.

3

Blemishes on buildings do not impart impurity until the abnormal appearance is seen below the surface of the wall, as implied by the term shika'rurot, interpreted as meaning "sunk in the walls," used by Leviticus 14:37. A blemish with either of these two appearances causes the building to be isolated or definitively deemed impure. If it increases in size, it should be torn down and if it spread after it was replastered, the entire house must be torn down, as will be explained.

4

When a blemish appears in a house, even a sage who knows that it is definitely a blemish should not definitively say: "A blemish appeared in my house." Instead, he should tell the priest, "It appears that a blemish appeared in my house. The priest will then issue an order to remove everything from the house, even bundles of wood and bundles of reeds. Afterwards, the priest will come and inspect the blemish.

5-6

We do not open windows in a closed house to inspect its blemishes. Instead, if a blemish is not visible in its present state, it is pure.

After a priest will inspect a blemish, he should depart and stand at the entrance to the house, near the lintel and either isolate, deem definitively impure, or release the house from the inspection process, as ibid.:38 states: "And the priest shall leave the house, going to its entrance... and he shall isolate the house." He should not isolate a house while he is in his own house, in the blemished house, or under its lintel. Instead, he should stand at the side of its entrance. If he stood under the lintel or went to his own house and isolated a house, it is isolated.

A house is not deemed impure because of a blemish unless it is four cubits by four cubits or more, it has four walls, and it is built on the earth with stones, earth, and wood, for Leviticus 14:45 mentions: "its stones, its wood, and its earth." If, however, it is less than four cubits by four cubits, it is round, triangular, or pentagonal, it was built on a ship or suspended on four beams, it is not susceptible to the impurity stemming from a blemish. If it was built on four pillars, it is susceptible to the impurity stemming from a blemish.

7

How many stones must be in a house? No less than eight, two stones on each wall so that every wall would be fit to have a blemish. For a house it is not susceptible to the impurity stemming from a blemish unless a blemish the size of two grisim appears on two stones, as indicated by Leviticus 14:40 which mentions: "the stones in which the blemish is located."

How many boards must it contain? Enough to place under the lintel. How much earth? Enough to place between one broken stone and another. If a house contained less than these measures, it is not susceptible to the impurity stemming from a blemish.

8

Neither bricks nor marble are considered as stones in this context. When there is a house that one of its walls is coated with marble, another is made from a boulder, the third, of stones, and the fourth, from earth, it is not susceptible to the impurity stemming from a blemish.

9

When a house did not have the required measure of stone, wood, and earth and a tzara'at blemish was discovered in it and then additional stones, wood, and earth was brought for it, it is pure.

10

When plants were used as the covering for a house, they are considered as a permanent part of it. Since they are serving the purpose of wood, they are considered as wood. If the house becomes impure, they contract the severe impurity associated with it, as will be explained.

11

Houses located in Jerusalem and the Diaspora are not susceptible to the impurity stemming from blemishes, as implied by Leviticus 14:34: "in a house in the land of your ancestral heritage." Jerusalem is thus excluded, because it was not divided among the tribes. The houses of gentiles in Eretz Yisrael are not susceptible to the impurity stemming from blemishes.

12

When one purchases houses from gentiles, they should be given an initial inspection.

13

When a gentile lives on one side of a house and a Jew on the other side or one side of a house was in Eretz Yisrael and the other in the Diaspora, it is not susceptible to the impurity stemming from blemishes. All other buildings in Eretz Yisrael are susceptible to the impurity stemming from blemishes. This applies regardless of whether they were colored naturally or colored because of human activity.

14

The house of a woman, a house belonging to partners, a synagogue or a house of study that has a dwelling for attendants or students is susceptible to the impurity stemming from blemishes.

15

The walls of a feeding stall and the walls of a partition in a house are not susceptible to the impurity stemming from blemishes.