《黄帝内经·灵枢·口问》
黄帝在闲暇独处的时候，屏退左右之后问岐伯说：我已经学到了九针针术方面的知识，也能判断阴阳顺逆的问题了，对六经也很熟悉，我还想学到一些你从别人的口述中了解的知识。
黄帝闲居，辟左右而问于岐伯曰：余已闻九针之经，论阴阳逆顺，六经已毕，愿得口问。
When the Yellow Emperor was leisurely alone, he asked Qi Bo after retiring to the left and right: I have learned the knowledge of nine-needle acupuncture and can also judge the problems of yin and yang, and I am also familiar with the six meridians. Some of the knowledge you have learned from other people's mouths.