black sheep), it can be rendered impure. laws of houses at least two afflicted stones are necessary for removal of any stones and at least two new stones must be used to fill the void. if the afflicted wall is shared by two houses owned by two neighbors, both neighbors must help to remove the afflicted stones, scrape and place the new stones, but only the owner of the house whose interior was afflicted performs the replastering. it is from this ruling that the proverb oy l'rasha, oy l'scheino (אוי לרשע אוי לשכנו, "woe to the wicked! woe to his neighbor!") originates. there are numerous limitations put on the tzaraath that afflicts houses: the house of a gentile is insusceptible to tzaraath. only houses that possess four walls and four corners are susceptible. similarly, only those houses that rest on the ground are susceptible, to the exclusion of those that are suspended above ground or are built on a boat. tzaraath only affects houses that are built entirely out of stones, wood and clay plaster. if any of the four walls are built or internally overlaid with marble, natural outcropping of rock, brick or earthen soil, that wall is insusceptible to tzaraath, and a house cannot be rendered impure unless all four walls are susceptible. two storey houses are treated as two distinct houses and the beams that serve as the floor of the upper storey and the roof of the lower storey are allowed to remain with whichever house remains. houses are the only buildings that are susceptible to tzaraath (not, for example, barns or cattle stalls) and only houses that exist within the region of land originally divided among the 12 tribes, because the verse refers to beis eretz achuzaschem (בית ארץ אחזתכם, "a house of the land of your inheritance"); this also excludes houses in jerusalem, because it was not given as an inheritance to any one tribe, but rather held jointly by all of israel. interpretations the talmud, and most historic jewish literature (for example rabbi samson raphael hirsch), regards tzaraath as a punishment for sin, and argue that cure from tzaraath only comes about through repentance and forgiveness. the verse itself arguably suggests this, as it directs those who find themselves afflicted to seek out a kohen (priest) and not a doctor, even though generally the torah encourages seeking medical treatment from doctors. the talmud lists seven possible causes for tzaraath: lashon hara ("evil tongue", i.e. malicious gossip), murder, a vain oath, illicit sexual intercourse, pride, theft, or miserly behavior. elsewhere, the connection with gossip is supported by the wordplay metzora (leper) - motzi ra (slanderer). one modern source asserts that as a "physical manifestation of a spiritual malaise," tzaraath is a "divine retribution for the offender's failure to feel the needs and share the hurt of others." in particular, midrash rabbah sees the different types of tzaraath as increasing levels of punishment, which could be curtailed at any stage if repentance was made: the first stage in the rabbah's view was the infection of homes, and if repentance came here it only required removal of the affected stones for a cure. in the second stage, the entire house must be torn down as the tzaraath would not go away, and the infection came upon one's clothes; if repentance came here it required only washing of the clothes for a cure. in the third stage of rabbah's scheme, the clothes must be burnt, and the infection enters the person's skin; if repentance occurs here then purification could occur. in the fourth stage, which only occurs when the person has completely refused to repent, the person is forced to dwell alone. each biblical victim of tzaraath is stated to have received the condition due to some violation of biblical laws, including joab for the murder of abner (whose blood was shed deceitfully in time of peace), gehazi (for 1. rebelling against elisha's decision to not take payment for a miracle god had worked 2. working deceitfully to take the payment 3. lying to elisha, saying he hadn't done the thing); and uzziah for burning incense in the temple (a ritual whose performance was limited to priests). other classical rabbinical writers saw tzaraath of houses as having a practical benefit. according to one, as well as being a punishment for miserliness, it also demonstrated that the house owner was lying, if they had said they did not own certain objects neighbours had asked to borrow, since the biblical regulations require the house owner to take all their possessions outside prior to confinement. on the other hand, rashi states that tzaraath of houses was a reward for the homeowner, arguing that the israelite homes had previously been those of canaanites, who had hidden their valuables in the walls; the tzaraath required the house owner to remove the bricks, and so find the treasures hidden there. the items used in the purification ritual - birds, cedar wood, and worm - were specifically included to deliver a message to the metzora. the sin most associated with tzaraath is lashon hara; to speak derogatorily about others to one's friends is likened to birds, who chatter endlessly. similarly, the one who speaks ill of others is haughty, holding himself or herself high above others, like the tall cedar. to be healed, the metzora must erase arrogance, making themselves lowly like a worm. this is a play on words—the word tola'as (תולעת) means both "red" and "worm" – as well as hyssop. current practice the laws of tzaraath are not practiced by contemporary jews. several approaches have been suggested to explain why this is the case: one could contract tzaraath nowadays, but this is practically irrelevant, because in the absence of a temple it is impossible to perform the tzaraath purification ritual, and because since the exile there is no commandment to remove tzaraath sufferers from the camp. one cannot formally acquire the status of tzaraath nowadays, since there are currently no priests with proven priestly lineage who can declare this status, or else because current priests do not have the necessary tradition or knowledge to determine the status, or because the temple robes which must be worn while declaring the status are unavailable. in times of exile tzaraath is not regarded as a direct divine punishment with a ritual remedy, but rather as a normal physical disease whose treatment is purely medical. modern medical interpretations ukrainian-jewish born yehuda l. katzenelson, (1846–1917) devoted a portion of his work on talmudic medicine to the analysis of the parallels between vitiligo and biblical tzaraath, he concluded that the chazalic consensus was that they are synonymous. tzaraath of the skin scholars suspect that the descriptions of tzaraath of the skin actually refer to a number of different skin diseases, which, owing to the undeveloped state of medical science at that period, were not distinguished. a wide range of diseases known to modern medicine have been suggested as differential diagnosis of tzaraath, including psoriasis, seborrhoeic dermatitis, favid, dermatophyte infections, nummular dermatitis, atopic dermatitis, pityriasis rosea, crusted scabies, syphilis, impetigo, sycosis barbae, alopecia areata, boil, scabies, lichen simplex chronicus, scarlet fever, lupus erythematosus, lichen sclerosus et atrophicus, folliculitis decalvans, morphea, sarcoidosis, and lichen planopilaris. of the particular situations that leviticus describes as being tzaraath, the whitening of the skin over the whole body with sores, is considered by scholars to be most indicative of psoriasis the spreading of sores is regarded by scholars as most symptomatic of impetigo the spreading of swellings or spots in a burn injury, according to scholars, is most probably a result of erysipelas in regard to subcutaneous disease where the hair has turned white the additional presence of swellings or spots in a burn injury are thought by scholars most likely to be tropical sores the additional presence of bodily sores, and swellings or spots where there previously had been a boil, is one of the classical symptoms of leprosy the additional presence of sores on the head or chin is thought by scholars to most probably indicate the presence of ringworm a white spot in the head or beard hair, called a netek, may be favus. russian pathologist gregory minh discovered that leprosy is contagious; assuming that biblical tzaraat is non-contagious, he therefore concluded that tzaraath is in fact vitiligo. similarly, reuven kalisher suggested that vitiligo is the most likely candidate for biblical tzaraath, as it is non-contagious, cause the hair located within the discolored area to turn white (also known as poliosis or leukotrichia), and can grow in size within a week to two-week period. yehuda l. katzenelson added that while vitiligo lacks the safachat characteristic of biblical tzaraat, the mishna (negaim, chapter 1) also does not mention this characteristic. however katzenelson concluded his analysis by listing many unanswered difficulties with minh's opinion. one recent author suggests that tzaraath in fact corresponds to no naturally occurring disease: "by establishing rigid criteria, almost everyone who was examined was destined to fail to meet the criteria for diagnosis. therefore this passage was designed to integrate persons with disfiguring skin diseases back into society, not to excommunicate them as was the practice in neighbouring societies." similar conditions not considered tzaraath in addition to simple rashes, inflammations, and swellings, the biblical text mentions a number of other conditions that could be confused with tzaraath. among other situations the text considers harmless are the appearance of dull white spots, white patches of skin without sores, and baldness without sores; the latter two of these are thought by scholars to most probably refer to vitiligo and alopecia, respectively, and the bible remarks that the former – the dull white spots – are merely a form of freckles. the symptoms that the text considers to be indicative of disease include those of the spread of superficial swellings or spots (where there had previously been a boil), and those of reddish-white sores in areas of baldness; the former condition is identified by the bible as plague, and scholars regard its symptoms as pointing to a diagnosis of smallpox, while the latter is unidentified in the biblical text, but considered by scholars to indicate favus. in clothing fabrics in addition to infecting the skin, tzaraath is described by leviticus as being able to infect historically common clothing fabrics, specifically wool, linen, and leather. the biblical description of tzaraath in such fabrics is strikingly analogous to that of tzaraath in the skin, with, for example, spreading of the infection being tested for by isolating the fabric in question for first 7 days. the principal symptoms are described as being green or red spots, which spread within a week, or that do not change appearance at all after a fortnight, having been washed after the first week, or that return a week after having been torn out, if they also had faded with washing prior to being torn out. these descriptions are regarded by scholars as most probably indicative of certain moulds, and especially matching infections by penicillium (the fungus that produces penicillin). in houses mildew infecting a flat dry rot the biblical text also describes tzaraath as infecting the walls of houses; the symptoms it describes are depressions in the wall, which are green or red, and spread over a period of seven days. the description is regarded by scholars as again being strikingly similar to the wording of the description of tzaraath infections in the skin, but still somewhat obscure; it would seem to fit some form of fungal growth, especially dry rot, which produces yellowish-green and reddish patches on walls.