《黄帝内经·灵枢·外揣》
九针的理论，可以说是精得不能再精，多得不能再多，深得不能再深，高得不能再高了，奥妙无穷，包罗万象，我知道九针之针道是与天道、人事、四季的变化相顺应的，而我想综合这些多如毫毛的论述，混合归纳成一个系统的体系，你看可以做到吗？
夫九针者，小之则无内，大之则无外，深不可为下，高不可为盖，恍惚无窍，流溢无极，余知其合于天道人事四时之变也，然余愿杂之毫毛，浑束为一，可乎？
The theory of the Nine Needles is as subtle as it could possibly be, and the knowledge is as extensive as it could possibly be; it is as profound as it could possibly be, and it is as lofty as it could possibly be, mysterious and rich in its meaning, containing everything within heaven and earth; I know that the method of the Nine Needles follows the changes of nature, human affairs, and the changing of the seasons; I wonder, could you combine these ideas as numerous as the hairs on a cow into a single, systematic whole?