“And the LORD spake unto Moses and unto Aaron, saying, When ye be come into the land of Canaan, which I give to you for a possession, and I put the plague of leprosy in a house of the land of your possession; And he that owneth the house shall come and tell the priest, saying, It seemeth to me there is as it were a plague in the house: Then the priest shall command that they empty the house, before the priest go into it to see the plague, that all that is in the house be not made unclean: and afterward the priest shall go in to see the house: And he shall look on the plague, and, behold, if the plague be in the walls of the house with hollow streaks, greenish or reddish, which in sight are lower than the wall; Then the priest shall go out of the house to the door of the house, and shut up the house seven days: And the priest shall come again the seventh day, and shall look: and, behold, if the plague be spread in the walls of the house; Then the priest shall command that they take away the stones in which the plague is, and they shall cast them into an unclean place without the city: And he shall cause the house to be scraped within round about, and they shall pour out the dust that they scrape off without the city into an unclean place: And they shall take other stones, and put them in the place of those stones; and he shall take other mortar, and shall plaster the house.” (Leviticus 14:33-42)
As I mentioned earlier, the word translated leprosy refers to far more than just what we call leprosy today. What as referred to as leprosy here is something like the black mold that invades homes in America. It causes many respiratory and other chronic problems, and requires severe remediation measures including removal of affected materials including drywall and wood placing them in a secure storage area to prevent spread of the organisms that cause it.
When the homeowner suspected such a problem, they were to contact the priests. The priest was to order the emptying of the house immediately to prevent spread of the mold. After the house was emptied. The priest was to inspect the house. If there were reddish or greenish streaks that appeared to be more than just a surface growth, they were to let the house sit empty for a week. After a week, they were to reinspect the house. If the streaks had spread, they were to have the infected stones removed and the rest of the walls scraped to remove any spores. The removed material was to be placed in a designated area where it would not be disturbed. The walls were then to be re-plastered, sealing the surface.
“And if the plague come again, and break out in the house, after that he hath taken away the stones, and after he hath scraped the house, and after it is plastered; Then the priest shall come and look, and, behold, if the plague be spread in the house, it is a fretting leprosy in the house: it is unclean.
And he shall break down the house, the stones of it, and the timber thereof, and all the mortar of the house; and he shall carry them forth out of the city into an unclean place. Moreover he that goeth into the house all the while that it is shut up shall be unclean until the even. And he that lieth in the house shall wash his clothes; and he that eateth in the house shall wash his clothes.” (Leviticus 14:43-47)
If the remediation efforts failed and the mold re-appeared, the entire house was to be demolished and the material taken to s designated disposal site. Anyone who entered the house was to avoid contact with others for the rest of the day, and anyone who spent significant time was to wash his clothing to be sure they did not spread the mold. It is essentially the same process that is followed today.
“And if the priest shall come in, and look upon it, and, behold, the plague hath not spread in the house, after the house was plastered: then the priest shall pronounce the house clean, because the plague is healed. And he shall take to cleanse the house two birds, and cedar wood, and scarlet, and hyssop: And he shall kill the one of the birds in an earthen vessel over running water: And he shall take the cedar wood, and the hyssop, and the scarlet, and the living bird, and dip them in the blood of the slain bird, and in the running water, and sprinkle the house seven times: And he shall cleanse the house with the blood of the bird, and with the running water, and with the living bird, and with the cedar wood, and with the hyssop, and with the scarlet: But he shall let go the living bird out of the city into the open fields, and make an atonement for the house: and it shall be clean.” (Leviticus 14:48-53)
If the remediation efforts were successful and the mold did not reappear, the house was declared safe for habitation. Two birds were to be offered in thanks giving. One was slain in a pottery vessel over running water. Cedar wood, hyssop, scarlet dye and the living bird were to be dipped in the blood of the slain bird and in the running water. They were then used to sprinkle the house seven times. The living bird was then released in the field and atonement made for the house.
“This is the law for all manner of plague of leprosy, and scall, And for the leprosy of a garment, and of a house, And for a rising, and for a scab, and for a bright spot: To teach when it is unclean, and when it is clean: this is the law of leprosy.” (Leviticus 14:54-57)
These instructions were given to help identify and prevent the spread of many of the common diseases of the time. Three thousand years later, they are still some of the most effective measures we have for preventing the spread of disease.