Literature Reference: 要传书札去，应到碛东云。—— 《送陆判官防秋》 Letters should be sent, reaching beyond the eastern desert clouds. Source from 'Song Lu Panguan Fangqiu'.
碛:
东: The East, the direction of the sunrise, symbolizes the essence of hope.
Meaning: Eastern desert symbolizes vastness and distance, embodying courage and perseverance.