“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.”
King James Version (KJV)
13:3 When the hair is turned white - This change of colour was an evidence both of the abundance of excrementious humours, and of the weakness of nature, as we see in old and sick persons. His flesh - For the leprosy consumed both the skin and the flesh.