律戒本疏 1.92

1.92

三十九不受飲食著口中墮　迦羅比丘塚間止住。死人之間食。輒自取食。眾人疑其常食死人。惡名流布。因是結戒。防譏嫌故。捨盜方便故。習大法故。棄世業故。故入口之物。一切應從淨人受。不受而食犯墮。不受而觸突。除水楊支輕賤易得故。無遮惜故。無貪積故。若非時人不與。不從淨人受。若菜菓等不作淨。若不淨食。食此五四三二一應如是知。食人肉偷。不淨故。大比丘手觸食不淨。食者犯突吉羅。若不如是一切無犯。

Thirty-nine: Putting food or drink into the mouth without having received it [is an offense of] pāyattika. The monk Kāla dwelt in a cemetery. Eating among corpses, he would take food on his own. The crowd suspected that he constantly ate dead humans, and an evil reputation spread abroad. For this reason, the precept was formulated: to guard against suspicion and criticism, to abandon the expedients of theft, to practice the Great Dharma, and to cast aside worldly occupations. Therefore, of things that enter the mouth, all must be received from a pure person. Eating without receiving incurs an offense of pāyattika; touching without receiving incurs a duṣkṛta. Excepted are water and tooth-sticks, because they are base and easily obtained, because there is no begrudging or sparing them, and because there is no greedy accumulation of them. If a person at an improper time does not give it, or if one does not receive it from a pure person, or if vegetables and fruits are not made pure, or if the food is impure—eating under these five, four, three, two, or one [conditions] should be understood in this way. Eating human flesh is a sthūlāccaya, because it is impure. If a fully ordained monk touches food with his hand, it becomes impure; one who eats it incurs a duṣkṛta. If not like these, in all cases there is no offense.