Leviticus 14:48-50

The Voice

⁴⁸ If the priest enters the house to inspect it and the spot has not reappeared after the walls have been rebuilt and replastered, the priest will declare the house clean because the spot has not returned. ⁴⁹ To cleanse the house from its contamination, the priest must take two birds, some cedar wood, scarlet string, and hyssop, ⁵⁰ and slaughter one bird in a clay jar over running water.