Moses was changed internally and externally by his experience on Mt. Sinai.
Provided by the Jewish Theological Seminary, a Conservative rabbinical seminary and university of Jewish studies.
The story is told about Franz Kafka that the last time he visited Berlin, he chanced upon a little girl in a park awash in tears. When he inquired as to the reason for her distress, she sobbed that she had lost her doll. Compassionately, Kafka countered that not to be the case. The doll had merely gone on a trip and, in fact, Kafka met her as she was about to leave. He promised that if the little girl would return to the park the next day, he would bring her a letter from her doll. And so Kafka did for several weeks, arriving each morning at the park with a letter for his new friend.
As his tuberculosis worsened, Kafka decided to return to Prague where he would soon die at age 41, but not before buying the girl another doll. Along with the doll came a letter in which Kafka insisted that this was the doll that belonged to his friend. Admittedly, she looked different, but then on her long trip the doll had seen many remarkable sights and gone through many searing experiences. Life had changed her appearance. (Jack Wertheimer, ed., The Uses of Tradition, p. 279).
Of the many meanings in this profound parable I wish to focus on the most obvious: that a transformative experience alters us externally as well as internally. This is the point of the closing narrative of our parashah. The second time that Moses ascends Mount Sinai to get the Ten Commandments--that is after the debacle of the golden calf--the Torah uncharacteristically gives us a profusion of details. In contrast to the brevity of description pertaining to his first ascent (Exodus 19:18-25; 24:1-4;31:18), the Torah now divulges that Moses stayed atop the mountain for 40 days and 40 nights without eating a morsel of bread or drinking a sip of water (34:28).
The intensity of this experience of the divine sets Moses' face aglow permanently, striking his people with fear. Thereafter, Moses would cover his face with a veil, except when he entered the Tent of Meeting to talk with God or when he addressed the nation (34:29-35).
This exceptional passage is marked by vocabulary equally rare. While the noun keren--meaning "horn"--shows up often in the Tanakh [Bible], the verb karan (same consonants), meaning "to emit rays," appears only here. Hence the mistranslation by the Vulgate to the effect that Moses came down with horns, a sign of sanctity. Similarly the noun for "veil" masveh, is unique to our narrative. Clearly, subject and language join to underscore the impact on Moses of being in God's presence for an extended period of time.