During the Spring and Autumn period, Duke Wen of Jin visited Duke Kang of Qin in the state of Qin. Duke Kang's mother was Duke Wen's sister, and seeing his uncle reminded him of her, far away with state affairs preventing a visit. Duke Kang often asked Duke Wen about his mother's daily life and meals, secretly grieving that he could not fulfill his filial duties by her side.
On the day Duke Wen of Jin was to return to his state, Duke Kang of Qin came to see him off, presenting him with a chariot of fine horses, jade, and precious gems as imperial gifts from the throne. Repeatedly, Duke Kang urged Duke Wen to send his regards to his mother, escorting him mile after mile. Each time Duke Wen begged him to stop, Duke Kang would weep. They traveled all the way to Weiyang, where Duke Kang finally halted his carriage and waved farewell to his uncle. Overcome with emotion and unable to contain himself, he spontaneously recited a poem.
I accompanied my uncle on his journey, all the way to the northern bank of the Wei River.
When asked what gift to present him, the emperor bestowed a chariot drawn by a yellow horse.
I send off my uncle, often thinking of my mother.
What gift should be given to him? Beautiful jade and precious gems of many kinds.
As Duke Wen of Jin's chariot faded into the distance, Duke Kang of Qin still gazed longingly after it. That was the direction where his mother lived!
Later, people used the idiom "Weiyang Affection" to refer to the bond between uncle and nephew.
Source: *Book of Songs*, "Airs of Qin", "Weiyang"
Meaning of the Idiom: Later, the Chinese idiom "渭阳之情" came to describe how the bond between uncle and nephew.