《黄帝内经·素问·八正神明论》
看不到形迹，尝不出味道，所以疾病于未发之时，就像幽灵一般飘渺难以诊治。
视之无形，尝之无味，故谓冥冥，若神髣髴。
Symptoms cannot be seen, and tastes cannot be detected, so when an illness is in its nascent stage, it is as elusive as a ghost and difficult to diagnose and treat.