Parsha Mitzvot: Metzorah: Mitzvah 174 – Concept 451
“On the seventh day he shall shave off all his hair; his head, his beard, his eyebrows, and all his hair shall he shave off; he shall immerse his clothing and immerse his flesh in water, and become pure (Vayikra 14:9).” The Metzorah must shave off all his hair prior to purification (Rambam, Hilchot Tumat Tzara’at – The Laws of Impurity Through Tzara’at).
The person shall see himself as if he were created on this day, and only today does his hair begin to grow, just as today he can begin anew to be clean of all falsehood and sin. (Chinuch)
The hair on his head to atone for arrogance and destructive thoughts. His beard to atone for sins committed with his mouth. His eyebrows to atone for seeing the world through stingy eyes, and allowing his eyes to lead him to sin. (Kli Yakar)