NOTES for Lev 14:1-32
The leper who has been healed of his disease is prescribed to be purified in exactly the same way as one is purified from sin. More precisely, not from sin itself, but from its consequences, because one can only repent of sin, while one must be purified from its consequences. What does such purification mean?
For a pagan, purification means above all a kind of hygienic procedure, only not physical but psychic and psychosomatic. It was supposed that in the world there is much from which a person's psychophysiology can suffer if it is allowed to affect human nature. What was usually considered purifying was something capable of shaking a person, of affecting his body and soul so as to make them experience a shock, greater or lesser. At the moment of such a shock, a person, as it were, "shook off" all stable psychophysical states imposed by external influences, experiencing this as purification, liberation from them.
In Yahwism, everything was not quite like that. Of course, being in God's presence and being sprinkled with sacrificial blood had a shaking effect on human nature, sometimes shaking even in the literal sense. But in this case something else also happened: the influence of God's presence could restore the psychophysical state that was normal for a person and allowed him then to be sanctified, at that same altar but through a separate sacrifice.
The consequences of sin destroyed above all a person's relationship with God; they destroyed it precisely because they changed his nature, adapting it to sin and death more than to life (and all the more to life in God's presence). The same thing happened when a person lived for years or even decades, in effect slowly dying, as lepers lived: his nature was transformed, adapting to death instead of adapting to the fullness of life. That is why the purification rituals and sacrifices had to stop this process of adaptation to death and turn it in the opposite direction, insofar as such a turn was possible at all in a world where death reigned.