Derech Mitzvosecha

You must rather use this as an opportunity to mend your ways and impr-- and improve your behavior.

In Derech Mitzvotecha, the Tzemach Tzedek explains the entire idea of tzaraas according to Chassidus, and in doing so explains these two commandments as well.

And the Tzemach Tzedek explains how it is that this skin condition comes about and why is it that it is-- it expresses itself through the skin turning white.

The Tzemach Tzedek explains that everything in the world gets its life, its chayis, its vitality from holiness, from kedusha.