He is a leprous man, he [is] unclean
And so to be pronounced and accounted; only a leprous man is mentioned, there being no leprous women, having this sort of leprosy, their hair not falling off, or they becoming bald, usually; unless, as Ben Gersom observes, in a manner strange and wonderful:
the priest shall pronounce him utterly unclean;
as in any other case of leprosy:
his plague [is] in his head;
an emblem of such who have imbibed bad notions and erroneous principles, and are therefore, like the leper, to be avoided and rejected from the communion of the saints, ( Titus 3:10 ) ; and shows that men are accountable for their principles as well as practices, and liable to be punished for them.