מִ֚י כְּהֶ֣חָכָ֔ם וּמִ֥י יוֹדֵ֖עַ פֵּ֣שֶׁר דָּבָ֑ר חָכְמַ֤ת אָדָם֙ תָּאִ֣יר פָּנָ֔יו וְעֹ֥ז פָּנָ֖יו יְשֻׁנֶּֽא׃
지혜자와 같은 자 누구며 사리의 해석을 아는 자 누구냐 사람의 지혜는 그 사람의 얼굴에 광채가 나게 하나니 그 얼굴의 사나운 것이 변하느니라
Likutei Moharan
The Jewish man needs to constantly look at (pay attention to) the intelligence (in other words meaning, or possibly spirituality) that is [surely in] everything. He must do this in order so the intelligence found in EVERYTHING will enlighten him to become closer to Hashem Yisborach through the very thing in which he see the intelligence.
Sefer HaMiddot
12. Those with pure vision can discern in a person who his rabbi is -- who taught him Torah. This is true specifically when the viewer is already familiar with the visage of the rabbi. For through the religious laws one learned from his rabbi, the face of the pupil becomes like the visage of the rabbi, for the Torah laws are his wisdom which illuminates his face, 'the wisdom of a man radiates from his face' (Kohelet -- Ecclesiastes 8:1). When the student receives the law, he receives a degree (/part) of his rabbi's visage, and the more laws he learns, the more degrees (/parts) of his visage will be accumulated.
Sefer HaMiddot
15. Those with pure eyesight can recognize in a man, who is the rabbi who taught him Torah. This is specifically when the one looking is familiar with the face of the rabbi. For through the religious law that a man learns from his rabbi, his face becomes similar to the appearance of the face of the rabbi, for the law is his wisdom that enlightens the face of a man (as in the verse, "The wisdom of man enlightens his face.") When one receives the law, one receives an aspect of the appearance of the teacher's face. And according to the amount of laws he learns, the more aspects of the appearance of his face are acquired.