A Physical Manifestation of Holiness
Many tzaddikim literally looked different on Shabbos. The holiness and radiance of Shabbos was changed their appearance.
A new bachur in the Mir Yeshiva heard the shiurim of the Mashgiach Reb Yeruchem zt''l throughout the week. When he heard him again on Shabbos, he questioningly turned to another bachur and asked him what the name of the "Shabbos mashgiach" is. Reb Yeruchem looked so different on Shabbos, that the bachur simply did not recognize him.
The Baal Haturim says that Parshas Vayakhel, which begins with the parshah of Shabbos, comes immediately after the pasuk (in the previous parshah) of קָרַן עוֹר פָּנָי מֹשֶׁה - in which the face of Moshe glowed, for on Shabbos the face of every Yid is illuminated.
(בעל הטורים ריש ויקהל)
