A Cohen may not inflict pain or degradation upon himself, by ripping out hair or lacerating his skin [for the tragedy of the loss of a relative]. He does Avoda in the Bais Hamikdash, the house of Hashem; and Chazal say that there is no sadness in front of Him. There cannot be any pain nor blemish [Mum] in His palace; only total Simcha and Shleimus. The eating of Kodashim must also be in a state of Simcha and royalty. The Torah forbids even a Yisroel from ripping hair or lacerating skin [for the loss of a relative]. We can suggest that every Yid should view himself as a Cohen, as we are a Mamleches Cohanim.
R' Yisroel Gelbwachs Shlita pointed out that our basic Shachris, Mincha, and Maariv correspond to the Avoda of the Cohanim. This is an incredible proof how Hashem wants us all to feel like Cohanim. Putting yourself down and underestimating yourself is also a type of laceration and ripping of hair. The message of these Lavin prohibitions is that we need to value ourselves and boost ourselves up!
