Millennium Suicide Note

In 210 BC, Shangjun. An edict was sent to Northern Xinjiang, ordering the eldest son Fusu to commit suicide. Fusu did not resist. Didn't ask. He drew his sword and said something—— "The father gave his son death, and Shang An asked him back." Then he died. But before he died, he wrote three letters. A letter to Meng Tian: Defend the northern border with 300,000 soldiers. A letter to Li Si: The Dharma is the skeleton, and people are flesh and blood. If the bones are too hard, the flesh will break. The third letter has no addressee - "The people of the world are enlightened". The letter was sewn into the lining of a piece of clothing and sank into a dry well along with a body. 2200 Years later, the dry well has long been filled up. The ink on the letter melted into the mud. But that sentence is still asking - why should people be justified in their lives?