大方便佛報恩經 6.75

6.75

He replied, “Four are offenses in themselves, and the single precept against drinking alcohol is a prohibitive offense. The reason why drinking alcohol is grouped with the four offenses to constitute the five precepts is that drinking alcohol is the root of negligence and can cause one to violate the four precepts. For instance, in the time of Kāśyapa Buddha, there was an upāsaka who, because of drinking alcohol, committed sexual misconduct with another's wife and stole and slaughtered another's chicken. When other people asked him, ‘Why did you do this?’, he answered, ‘I did not do it.’ Because he was deranged by alcohol, he was able to break all four precepts at one time. There are those who, because of drinking alcohol, can commit the four heinous deeds, being unable only to cause a schism in the Saṅgha. Although it is not past karma, it brings the retribution of madness: because of drinking alcohol, one becomes confused and deranged, just like a madman. Moreover, being deranged by alcohol, one abandons one's proper tasks—sitting in meditation, reciting scriptures, and assisting with the affairs of the community. Although it is not an offense in itself, by this reason it is treated the same as an offense in itself.”