Leviticus 13:22

And if it spread much abroad. — If, on inspecting it again at the end of the seven days’ seclusion, the priest finds that the spot has spread, it was evident that the blood was vitiated, and that the distemper began to develop in the body.

It is a plague. — That is, of leprosy. The word “leprosy,” which has here dropped out of the text, is still preserved in some of the ancient versions.