In the Han dynasty, Shu Guang and Shu Shou served together as tutors to the crown prince. After five years, Shu Guang said: “Know when enough is enough, and there is no disgrace. Withdraw when the work is done, that is the way of Heaven.” On the same day, both reported sick.
After three months of sick leave, Shu Guang said that his illness was serious and petitioned to “beg for his bones” (乞骸骨), the old formula for asking to retire. The emperor agreed and gave them twenty jin of gold. Hundreds of carriages saw them off.