Leviticus 13:30
the priest shall examine the infection, and if it appears to be deeper than the skin and the hair in it is yellow and thin, the priest must pronounce him unclean; it is a scaly outbreak, an infectious disease of the head or chin.

Leviticus 13:34
On the seventh day the priest shall examine the scaly outbreak, and if it has not spread on the skin and does not appear to be deeper than the skin, the priest is to pronounce him clean. He must wash his clothes, and he will be clean.

Leviticus 13:36
the priest is to examine him, and if the scaly outbreak has spread on the skin, the priest need not look for yellow hair; the person is unclean.