Yide 懿德 is a common phrase in Classical Chinese texts. Hitherto, Yide is interpreted as "virtue" and there has been no controversy. However, in "The Will of Jigong" [Jigong zhi guming] of the Tsinghua Bamboo Stripes, Yide 懿德 is written as □德. In the newly published "The Four Instructions" of the Tsinghua Bamboo Stripes, there is a new version of the phrase in which the "yi" is written as a combination of 壹 and 印. This paper argues that Yide 懿德 should be interpreted as "the virtue of self-denial" rather than the "virtue". This new understanding enhances our knowledge of ancient Chinese texts.