Leviticus 13: 45-46:
The leprous person who has the disease shall wear torn clothes and let the hair of his head hang loose, and he shall cover his upper lip and cry out, “Unclean, unclean.” He shall remain unclean as long as he has the disease. He is unclean. He shall live alone. His dwelling shall be outside the camp.
The Levitical law shares this healthy fear of blight. If fabric showed evidence of mold, it was defiled. A house that showed persistent signs of mold had to be torn down. If not eradicated, mold will spread to whatever it contacts. The laws about mold are mixed in with laws about leprosy. As long as a skin disease was deemed persistent, the person with the disease had to remain apart from the community.
Like mold on peaches, defilement spreads in only one direction. The Israelite who touched someone unclean became defiled because defilement travels from the unclean to the clean.
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