Leviticus 13:32-36

And on the seventh day the priest shall look at the infection, and if the scale has not spread and no yellowish hair has grown in it, and the appearance of the scale is no deeper than the skin,

then he shall shave himself, but he shall not shave the scale; and the priest shall isolate the person with the scale for seven more days.

Then on the seventh day the priest shall look at the scale, and if the scale has not spread in the skin and it appears to be no deeper than the skin, the priest shall pronounce him clean; and he shall wash his clothes and be clean.

But if the scale spreads farther in the skin after his cleansing,

then the priest shall look at him, and if the scale has spread on the skin, the priest need not look for the yellowish hair; he is unclean.