《黄帝内经·素问·移精变气论》
现时，内则为忧患所牵累，外则为劳苦所形役，又不能顺从四时气候的变化，因此常常遭受到虚邪贼风的侵袭，正气衰弱在先，外邪乘虚而袭于后，内犯五脏骨髓，外伤孔窍肌肤，这样轻病必重，重病必死，所以用祝由法就不能医好疾病了。
当今之世不然，忧患缘其内，苦形伤其外，又失四时之从，逆寒暑之宜，贼风数至，虚邪朝夕，内至五脏骨髓，外伤空窍肌肤，所以小病必甚，大病必死，故祝由不能已也。
Now, the internal is affected by worries, the external is taxed by hardship, and is not following the changes of the four seasons. Thus, often attacked by malevolent wind, the righteous qi is weakened first, and the external evil takes advantage of the situation and invades later. Internally attacks the five internal organs and bone marrow, externally hurts the orifices and skin. In this way, a minor illness will become serious, and a serious illness will be fatal. Therefore, the zhuyou method cannot cure illnesses.