Leviticus 13:7-8, 22, 27, 36, 51

But if the rash continues to spread after the person has been examined by the priest and has been pronounced clean, the infected person must return to be examined again. If the priest finds that the rash has spread, he must pronounce the person ceremonially unclean, for it is indeed a skin disease.

If during that time the affected area spreads on the skin, the priest must pronounce the person ceremonially unclean, because it is a serious disease.

On the seventh day the priest must examine the person again. If the affected area has spread on the skin, the priest must pronounce that person ceremonially unclean, for it is clearly a serious skin disease.

the priest must do another examination. If he finds that the sore has spread, the priest does not need to look for yellow hair. The infected person is ceremonially unclean.

On the seventh day the priest must inspect it again. If the contaminated area has spread, the clothing or fabric or leather is clearly contaminated by a serious mildew and is ceremonially unclean.