In the preface to send Li Pangu. Zhuo: Wash. Throw clear spring water to wash yourself. Always remain spotless. Here, "Zhuo qingquan" is a metaphor for people's self-moral cultivation. It can be used to describe people's often introspective behavior, and it can also be used to cultivate their own sentiments with progressive theoretical works and literary works.

Han Yu, a writer in the Tang Dynasty, sent Li Yuan to Pangu in sequence.

Books cultivate sentiment. Bo Wei, a famous saying that cultivates sentiment

The beauty of the surrounding world can cultivate students' sentiment, make them noble, elegant, compassionate and hate ugly behavior. Soviet educator Suhomlinski