Literature Reference: 故人天一涯，久客殊未回。雁来不得书，空寄声哀哀。—— 《鼓吹曲辞 临高台》 My old friend is at the end of the sky, long a traveler who has not returned. The wild geese come but bring no letter, only my voice sent in vain, sorrowful and mournful. Source from '鼓吹曲辞 临高台'.
空: The heavens, the expanse.
寄: "Entrustment, a conveyance of hope and reliance. In names, it often signifies the presence of support and a steadfast foundation."
Meaning: Kong Ji conveys the sorrow and longing that cannot be delivered, expressing deep loneliness and helplessness.