Clothing for Tzadikim
Rashi states: To sanctify him, so that he serve Me: To sanctify him, to initiate him into the kehunah through these garments so that he would be a kohen to Me.”
It is related that there once was a big lamdan who opposed the chasidim. He came to the Netziv of Volozhin zy”a and complained that Chasidic Rebbes dress royally and walk around in the streets like kings in fancy clothing, whereas Roshei Yeshivos and Gedolei Torah dress simply and live poor lifestyles.
The Netziv replied, “This is how it has always been. Aharon Hakohen was the Rebbe. He performed the Avodah in the Mikdash. Therefore, he wore golden clothes, bedecked with precious gems. Moshe Rabenu was the Rosh Yeshiva. He taught Torah to Klal Yisroel. And we don’t find that he wore any special clothing.”