釋禪波羅蜜次第法門 2.115

2.115

第一、調食者，夫食之為法本，欲資身進道，食若過飽，則氣急身滿，百脈不通，令心閉塞，坐念不安。若食過少，則身羸心懸，意慮不固。此皆非得定之道。復次，若食穢濁之物，令人心識惛迷；若食不宜身物，則動宿疾，使四大違反。此為修定之初，深須慎之，故云身安則道隆。經云：「飯食知節量，常樂在閑處，心靜樂精進，是名諸佛教。」

First, regulating food: food is the basis of the body, intended to support the physical form and advance in the Way. If one eats to excess, the breath becomes rushed, the body feels bloated, the channels do not circulate, the mind becomes blocked, and one cannot sit peacefully in mindfulness. If one eats too little, the body becomes emaciated, the mind unsettled, and thoughts unstable. Neither of these is the way to attain concentration. Furthermore, if one eats contaminated and foul substances, it causes the mind and consciousness to become dull and confused; if one eats things unsuited to the body, it stirs up chronic ailments and causes the four great elements to conflict. At the beginning of cultivating concentration, one must be deeply cautious of this; hence it is said that when the body is at peace, the Way flourishes. The sūtra says: “Knowing moderation in eating food, constantly delighting in quiet dwellings, with a tranquil mind delighting in vigor—this is the teaching of all Buddhas.”