During the Long'an era of the Jin Dynasty, Wu Yin-zhi was appointed as the governor of Guangzhou. On his journey, he passed by a place called Shimen, where there was a spring known as 'Greed Spring' (Tan Quan).

Locals warned him that anyone who drank from this spring would become greedy. Wu Yin-zhi, however, did not believe this superstition. He drank from the spring and composed a poem which read: 'The ancients called this water, a single sip, a thousand pieces of gold it incites. Yet, if Bo Yi and Shu Qi were to drink, their hearts would surely not change.'

After he took office, Wu Yin-zhi consistently maintained a lifestyle of integrity and purity, demonstrating his unyielding incorruptibility, just as he vowed.