It is an old leprosy in the skin of his flesh, and the priest shall pronounce him unclean, and shall not shut him up: for he is unclean.
Instructions for diagnosing chronic skin conditions given to priests.
King James Version (public domain)
Traditionally attributed to Moses · c. 13th century BC · The Pentateuch — Genesis, Exodus, Leviticus, Numbers, and Deuteronomy — is traditionally attributed to him
9When the plague of leprosy is in a man, then he shall be brought unto the priest;
10And the priest shall see him: and, behold, if the rising be white in the skin, and it have turned the hair white, and there be quick raw flesh in the rising;
11It is an old leprosy in the skin of his flesh, and the priest shall pronounce him unclean, and shall not shut him up: for he is unclean.
12And if a leprosy break out abroad in the skin, and the leprosy cover all the skin of him that hath the plague from his head even to his foot, wheresoever the priest looketh;
13Then the priest shall consider: and, behold, if the leprosy have covered all his flesh, he shall pronounce him clean that hath the plague: it is all turned white: he is clean.