Leviticus 13:38-46

So infinitely important is the doctrine of being convinced of a leprous state, and of the impossibility of being cleansed by anything short of divine power; that the HOLY GHOST prosecutes in these verses the same subject. The leper is here shown the dreadful state of being shut out, while the disease remained uncured, from all civil or religious communion. And as an evidence that he himself is conscious of it, he is continually to keep in mind and as frequently to cry out, by way of deterring any from approaching him, unclean, unclean. And what was all this designed to show, but that, in a gospel sense, when the heart is thoroughly awakened by almighty grace, to a knowledge of its own sinfulness and loathsomeness before GOD, to manifest by retirement from the world, and lying low in the dust under a deep sense of humiliation, that the unhumbled heart is at length subdued, and the man accepts the punishment of his iniquity. Covering the upper lip, renting the clothes, dwelling alone, and walking with the head bare; all these are so many outward signs, of an inward sorrow of soul. The church is represented as speaking this language of penitence by the prophet, when confessing we are all as an unclean thing. Isaiah 64:6.