These are the rules regarding spreading: If the lesion on the skin of his flesh is a snow-white or lime-white spot, whose appearance is deeper than that of the unaffected skin, or a wool-white or egg-membrane-white spot, whose appearance is not deeper than that of the unaffected skin, but no previously dark hairs have turned white since the appearance of the lesion and there is no patch of healthy skin within the lesion (as will be described presently), then the priest must quarantine the person with the lesion in a separate house for seven days, during which the priest must not see him, in order that the priest be able afterward to discern whether the lesion has spread during this time.
The quarantined individual is considered ritually defiled to the same extent as someone who has been conclusively diagnosed as afflicted with tzara’at. Nonetheless, he is not to be banished from the camp (or later, after we will be organized into three concentric camps, from all three camps), as is someone who has been conclusively diagnosed, as will be discussed later.
On the seventh day, the priest must examine him. If (a) the lesion has remained the same in its appearance, i.e., color, and (b) the lesion has not grown and spread on the skin, and (c) no previously dark hairs within it have turned white, and (d) no patch of healthy flesh has appeared within it (as will be described presently), the priest must quarantine him for seven days a second time. If, however, the lesion spread, covering more (but not all) of his body; or previously dark hairs within it turned white; or a patch of healthy flesh appeared within it; the priest must pronounce him defiled. In contrast, if the lesion either shrunk or became darker to the extent that it no longer qualifies as one of the four types of white spots mentioned above, the priest must pronounce him rid of this defilement and he must undergo the purification process that will be detailed later.
The seventh day of the first quarantine week also counts as the first day of the second quarantine week.
