法苑珠林 88.118

88.118

問曰。諸經論中何名八關齋。亦名關戒耶。答曰。前八是關閉八惡不起諸過。不非時食者。是齋。齋者齊也。謂禁止六情不染六塵。齊斷諸惡具修眾善。故名齋也。又齋戒體一名別。若尋名定體。體容小別。齋者過中不食為名。戒者防非止惡為義。故薩婆多論云。八箇是戒。第九是齋。齋戒合數故有九也。

Question: In the sūtras and treatises, why is it called the "Eight-fold Upavāsa" and also called the "Precepts of the Barrier"? Answer: The first eight are the closing of the barrier against the eight evils so that various faults do not arise. Not eating after midday is the fasting (zhāi). Fasting (zhāi) means "to equalize" (qí): it means curbing the six emotional senses so they are not defiled by the six dusts, evenly severing all evils, and fully cultivating all goods; hence it is called zhāi. Moreover, the essence of the fast and the precept is one, while their names are distinct. If one determines their essence according to their names, their essences allow for a slight distinction: "fasting" (zhāi) is named after not eating past noon, while "precept" (jiè) has the meaning of preventing wrongdoing and stopping evil. Thus the Sarvāstivāda-śāstra states: "Eight are precepts, and the ninth is the fast. Counting the fast and the precepts together, there are nine."