Mutar things are redeemable, Assur things aren’t. There are two ways Issur is redeemed A. after Moshiach comes and Hashem removes the evil totally, like the idea of הכל חוזרין לעפרן רגע קודם התחי’ה. The Rebbe’s idea that this can be realized through ונפשי כעפר לכל תהי’ה

Klipas Noga goes down when one indulges with lust. The explanation of נבל ברשות התורה. Correction by using לשם שמים is like the קרבן עולה is returning to Hashem. The idea of מותר is untied and of אסור is tied down.