The source of Liu Yong's "Hard to Leave" is: "Natural, gentle and blue-hearted, beautiful and handsome, and valuable." This word describes a woman with a kind heart and noble quality, and is a metaphor for a woman with a pure heart and an elegant personality. Wisdom and blue heart describe the beautiful characteristics of women, while Mei Shaorong describes the beautiful appearance of women. This word means that a woman has noble qualities and a beautiful appearance, which is priceless.