Literature Reference: 橘怀乡梦里，书去客愁中。—— 《同邬戴关中旅寓》 Amidst the dreams of hometown and the departure of letters, the traveler's sorrow lingers. Source from 'Tong Wu Dai Guan Zhong Lv Yu'.
书: Books, repositories of knowledge, embody wisdom. They express art and literature, convey profound thoughts, facilitate emotional expression, and are adorned with literary elegance.
去: To go from one's current location to another place, in contrast to "coming."
Meaning: The departure of letters symbolizes the conveyance of deep emotions and solace.