Leviticus 13:1-3

And the LORD spake unto Moses and Aaron, saying, When a man shall have in the skin of his flesh a rising, a scab, or bright spot, and it be in the skin of his flesh {like} the plague of leprosy; then he shall be brought unto Aaron the priest, or unto one of his sons the priests: {rising: or, swelling} And the priest shall look on the plague in the skin of the flesh: and {when} the hair in the plague is turned white, and the plague in sight {be} deeper than the skin of his flesh, it {is} a plague of leprosy: and the priest shall look on him, and pronounce him unclean.