Literature Reference: 老偿文债负，宿结字因缘。—— 《江楼夜吟元九律诗成三十韵》 Repaying the debt of writing in old age, long tied by the karma of characters. Source from 'Jiang Lou Ye Yin Yuan Jiu Lü Shi Cheng San Shi Yun'.
字: Script, Chinese characters.
因: The cause, the reason, the pre-existing conditions that lead to the occurrence of an event.
Meaning: The karma of characters signifies a profound connection with words, symbolizing literary talent and destiny.