金玉其质

Explanation: Quality: the nature, quality. Refers to the quality of virtuous people. 　　Source: Qing Li Ruzhen "Flowers in the Mirror" Jin Bu Wei, the first back to its quality, but also for the heart and the snow and ice. " 　　Examples: Bu ~, and the snow is also the heart. (Ching Li Ruzhen "mirrors" the first return)