Lev Leviticus, chapter Book of Leviticus, chapter 13
If a man or woman have a plague upon the head or the beard;
Then the priest shall see the plague: and, behold, if it [be] in sight deeper than the skin; [and there be] in it a yellow thin hair; then the priest shall pronounce him unclean: it [is] a dry scale, [even] a leprosy upon the head or beard.