In Chinese, the word "Sangzi" is often used to refer to "hometown, countryside". This usage has been formed in the Eastern Han Dynasty at the latest, because Zhang Heng of the Eastern Han Dynasty had a sentence in his "Ode to the Southern Capital": "Forever friends and filial piety will cherish their hometown; when a real person visits the south, he will return home."

Due to the above reasons, over time, mulberry and catalpa trees have become symbols of hometown, and "mulberry" has become synonymous with hometown. For example, Cai Yan, a female poet during the Three Kingdoms period, has a sentence in "Eighteen Beats of Hujia" (some say it is a pseudonymous work): "If you are still alive, you still hope to return to your hometown, and if you die, your bones will be buried for a long time.", Western Jin Dynasty The writer Lu Ji's "Ode to Missing Family" and the Southern Dynasty poet Xie Lingyun's "Ode to Xiaogan" also have sentences respectively: "Sad for the vastness of the mulberry home, I feel ashamed that the prime minister has tasted the unforgivable camp", "I am lingering in love with the graves, and I am worried. No tears at all."

This usage is more common in poems of the Tang Dynasty, such as: "I will always cherish my hometown, and I will return when I grow old" (Li Deyu's "Remembering Pingquan Bieye in Early Spring at Yanchan Gongfa Hall" (written by Jinling) ”, “Country birds also come here for whatever reason, which makes me remember my hometown” (Liu Zongyuan’s “Wearing the Oriole”), “I returned home after my illness, and I went to my hometown”

Sangzi refers to my hometown, Sheji. Refers to the country, and Hongyan refers to the letter. Extended information

Sangzi, in ancient times, people liked to plant mulberry trees and catalpa trees around their houses. Later, people planted mulberry trees and catalpa trees to raise silkworms. In order to light lamps (the white outside of the seeds of the catalpa tree is the wax of candles, and the wax on the candles used by people before modern times was obtained from the catalpa tree)

The ancients planted mulberry trees for clothing. Planting hemp. "Mencius" said: "A five-acre house should be planted with mulberry trees, and those who are fifty can wear silk clothes." Therefore, the word "mulberry hemp" is used exclusively to refer to farming. The Tang Dynasty poet Meng Haoran said in "Guo Fangzhuang" In the poem, there is a sentence: "Open the garden in front of the garden, talk about mulberry and hemp over wine".

In ancient times, people often planted mulberry and catalpa beside their houses. "The Book of Songs·Xiaoya" said, "Weisang and catalpa. "Must be respectful and stop" means that Sang and Zi can easily arouse the nostalgia for parents. Later, "Sangzi" was used as a proxy for "hometown".

Reference: Baidu Encyclopedia-Sangzi