This is a famous saying of Confucius, which comes from The Analects of Confucius. It means that a person should check his virtue three times a day in order to constantly improve and maintain noble character.

In this sentence, "I" refers to self, "province" refers to introspection, "body" refers to one's own behavior and thoughts, and "virtue and fragrance" refers to the nobility and beauty of moral character. The whole sentence expresses Confucius' emphasis on personal cultivation and self-improvement. He believes that only by constantly reflecting on his thoughts and behaviors can he constantly improve his moral cultivation, thus achieving the perfection of his personality and social harmony.

This sentence also reflects the Confucian thought of "cultivating oneself, governing the country and calming the world", that is, through personal cultivation and self-improvement, family harmony, national prosperity and world peace can be achieved. In contemporary society, this sentence also provides a good guide for our personal growth and cultivation, that is, we should always reflect on our words and deeds, take honesty, trustworthiness, awe and respect as the criteria, and constantly improve our moral cultivation, so as to become a valuable person.