During the Jin Dynasty, there was a prefect of Yuzhang named Yin Xian, whose courtesy name was Hong Qiao. When he was about to leave his post, many people, knowing he was returning to the capital, entrusted him with letters to be delivered to their families and friends in his hometown. At that time, there was no organized postal service, so people relied on acquaintances to carry their mail.

Hong Qiao politely accepted over a hundred letters. However, upon reaching Shitou Isle during his journey, he threw all the letters into the river.

When people subsequently did not receive their letters, they often associated the loss with Hong Qiao, realizing he must have discarded them. This incident gave rise to the idiom "fu zhu Hong Qiao," meaning to lose or discard entrusted letters.