Leviticus 13:6

3 And if, when the priest sees the mark on his skin, the hair on the place is turned white and the mark seems to go deeper than the skin, it is the mark of a leper: and the priest, after looking at him, will say that he is unclean.

4 But if the mark on his skin is white, and does not seem to go deeper than the skin, and the hair on it is not turned white, then the priest will keep him shut up for seven days;

5 And the priest is to see him on the seventh day; and if, in his opinion, the place on his skin has not become worse and is not increased in size, then the priest will keep him shut up for seven days more:

6 And the priest is to see him again on the seventh day; and if the mark is less bright and is not increased on his skin, then let the priest say that he is clean: it is only a skin-mark, and after his clothing has been washed he will be clean.

7 But if the size of the mark on his skin is increased after he has been seen by the priest, let him go to the priest again:

8 And if, after looking at him, he sees that the mark is increased in his skin, let the priest say that he is unclean; he is a leper.

9 When the disease of a leper is seen on a man, let him be taken to the priest;