Parshas Mitzora: from Revach.net
Rav Moshe Feinstein – Because We Don’t Know As Much As We Think
“V’tziva HaKohen V’Lakach LaMitaher; The Kohen commands the one who is becoming Tahor.” (Mitzora 14:4) Rav Moshe Feinstein says that it seems from here that the Mitaher must be commanded each step of the process by the Kohen. “Where do we find such a thing,” asks Rav Moshe, “where the Torah specifically includes in the process that the person be told by someone else to do something?”
Rav Moshe answers that there are certain mitzvos whose exact details are perceived by people to be outside the realm of dictated halacha and are left to a person’s logical discretion. In those cases, the person acts on his own feelings and not the dictates of the Torah. For example, when giving tzedaka people feel it is their right to use their own judgement, even though there are halachos as to where your tzedaka should go. Similarly, parenting is something that people do without consulting halacha and use their own “good sense”.
One of the reasons for Tzoraas is not lending your possessions to others. This is because a person feels that lending is at his own discretion. As part of his tikun, the Torah teaches him that he cannot make a single move that is not firmly rooted in halacha. Therefore, when going through the tahara process, he has a Kohen alongside of him guiding him on his every move.