“וְהָי֥וּ עֵינֶ֖יךָ רֹא֥וֹת אֶת־מוֹרֶֽיךָ”

 

The Chatam Sofer writes (Parashat Vayishlach) that when one looks at the face of a Tzadik, it makes an impression on the person for the good. Similarly, the Arizal Hakadosh writes that looking at the face of a tzadik purifies one's neshama.