Tears shed on the eaves "was an idiom that originated from Du Fu's poem" Remembering My Younger Brother in the Moonlit Night "of the Tang Dynasty: " The black geese fly high in the moon and the Chanyu flees at night. I want to lead the light cavalry to chase the heavy snow, bow and knife full. This place is a farewell to the lonely Peng Wanli expedition. The autumn on the border is bleak, the weather is cold, and the grass is luxuriant. I received the letter last night asking when you will return it? Friends and relatives in Luoyang are like asking each other. A piece of ice heart is in the jade pot. Tears shed on the eaves, wet my silk clothes, and from then on, I miss the two places far away." In this poem,"tears shed on the eaves" described the sad scene of parting. In ancient literature, there were many descriptions of " tears shed from the eaves ". For example, Bai Juyi's " Farewell to the ancient grass " of the Tang Dynasty: " The grass on the plains withers and thrives every year. The wildfire never ends, and the spring breeze blows, it grows again. The far-off fragrance encroaches on the ancient road, the clear green connecting the deserted city. And send the prince to the lush garden to bid farewell." In the Tang Dynasty, Wang Zhihuan's " Climbing the Stork Tower ":" The sun is against the mountains, and the Yellow River flows into the sea. I want to see a thousand miles and reach a higher level." Among them,"going to the next level" implied the reluctance to part and the yearning for the future. There was also Su Shi's "Jiangcheng Zi·Yimao Dream on the 20th Night of the First Month" of the Song Dynasty: "Ten years of life and death are boundless and unforgettable. A lonely grave thousands of miles away, I have no place to talk about desolation. Even if we meet again, we should not know dust, face and hair like frost. In the dark night I dreamed that I had suddenly returned to my hometown, and was dressing by the window of my cottage. We look at each other without saying a word, only a thousand lines of tears. I've been expecting my heart to break year after year on the moonlit night in the pine hills." The description of "tears on the eaves" appeared in the thirty-first chapter of Su Shi's "Jiangcheng Zi·Dream on the 20th Night of the First Month of Yimao".