And the leper in whom the plague [is],.... Meaning not he only that has the plague of leprosy in his head, but every sort of leper before mentioned in this chapter:his clothes shall be rent; not that he might the more easily put on his clothes without hurting him, as some have thought; or that the corrupt humours might evaporate more freely, for evaporation would rather be hindered than promoted by being exposed to cold; nor that he might be known and better avoided, for his cry after mentioned was sufficient for that; but as a token of mourning: and so Aben Ezra having mentioned the former reason, that he might be known by going in a different habit, adds, or the sense is, as a token of mourning; for he was to mourn for the wickedness of his actions; for, for his works came this plague of leprosy upon him; and so the Jews in common understand it, not as a disease arising from natural causes, but as a punishment inflicted by God for sin; wherefore this rite of rending the garments was an emblem of contrition of heart, and of sorrow and humiliation for sin, see Joe 1:13:and his head bare; or "free" from cutting or shaving, but shall let his hair grow; and so the Targum of Jonathan and Jarchi interpret it; or free from any covering upon it, hat, or cap, or turban: Ben Gersom observes, that the making bare the head, or freeing it, is taken different ways; sometimes it is used of not shaving the head for thirty days, and sometimes for the removal of the vail, or covering of the head it has been used to; but in this place it cannot signify the nourishing of the hair, but that his head ought to be covered: and so Maimonides observes, that a leper should cover his head all the days he is excluded, and this was a token of mourning also; see 2Sa 15:30:and he shall put a covering upon his upper lip; as a mourner, see Eze 24:17.
Jarchi interprets it of both lips, upper and under, which were covered with a linen cloth or vail thrown over the shoulder, and with which the mouth was covered; and this was done, as Aben Ezra says, that the leper might not hurt any with the breath of his mouth;and shall cry, Unclean, unclean; as he passed along in any public place, that everyone might avoid him, and not be polluted by him: the Targum of Jonathan is,"a herald shall proclaim and say, Depart, depart from the unclean.'
'So every sinner sensible of the leprosy of sin in his nature, and which appears in his actions, should freely confess and acknowledge his uncleanness, original and actual, the impurity of his heart and life, and even of his own righteousness in the sight of God, and have recourse to Christ, and to his blood, for the cleansing him from it.
Hilchot Tumaat Tzarat, c. 10. sect.