摩訶止觀 8.73

8.73

四大不順者：行役無時，強健擔負，棠觸寒熱，外熱助火，火強破水，是增火病；外寒助水，水增害火，是為水病；外風助氣，氣吹火、火動水，是為風病；或三大增害於地，名「等分病」；或身分增害三大，亦是等分，屬地病。此四既動，眾惱競生。

As for disharmony of the four great elements: laboring without regular hours, exerting oneself to carry heavy burdens, repeatedly coming into contact with cold and heat—external heat assists fire, and strong fire destroys water, which is an increase of fire illness; external cold assists water, and an increase of water harms fire, which is a water illness; external wind assists qi, the qi blows the fire, and the fire stirs the water, which is a wind illness; or three elements increase and harm the earth, which is called an 'equally-proportioned illness'; or the physical bodily parts increase and harm the other three elements, which is also equally proportioned and belongs to earth illness. Once these four are stirred, numerous afflictions arise in competition.