大乘百法明門論開宗義決 1.28

1.28

執鷄狗等諸戒清淨等者。為有外道得世定通。見鷄狗牛死已生天。或見露形或墮灰土或受苦惱得生天上。不能善知緣起道理。起如是見立如是論。學彼狗等而持彼戒。是名清淨皆得生天。或有妄執紛陀利河婆呼陀河伽耶河兢伽河等其水清淨。於中沐浴所有罪障一切除滅皆得生天。今應問彼計清淨者。執受淨物行淨行故得清淨耶。為受穢物行惡行故得清淨耶。若由執淨行淨行者。世間共許狗惡不淨。而汝許執受狗等戒得清淨者。不應道理。若執不淨行惡行故得清淨者。自惡不淨能令他淨。不應道理。又由內淨故究竟淨。為外淨故究竟淨耶。若由內淨者。河水沐浴而得清淨。不應道理。若由外淨者。內具垢惑但除外垢。不應道理。

Regarding "holding that the precepts of chickens, dogs, and the like bring purity," and so forth: There were non-Buddhists who attained worldly meditative stabilization and supernormal powers, and saw chickens, dogs, or cattle being reborn in heaven after death; or they saw going naked, falling into ashes and dirt, or undergoing afflictive torments resulting in rebirth in heaven. Unable to properly understand the principle of dependent origination, they formed such views and established such doctrines: "Imitating those dogs and the like and maintaining their precepts is called purity, and all will attain rebirth in heaven." Or there were those who falsely held that the waters of the Puṇḍarīka River, the Bahudā River, the Gayā River, the Gaṅgā River, and so forth are pure, and that bathing in them will eradicate all sinful hindrances and all will attain rebirth in heaven. Now one should question those who assert this purity: Is it because of undertaking pure things and practicing pure conduct that one attains purity, or is it because of receiving defiled things and practicing bad conduct that one attains purity? If it is due to undertaking what is pure and practicing pure conduct, the world universally agrees that dogs are bad and impure; thus for you to allow that undertaking the precepts of dogs and the like brings purity is unreasonable. If it is because of undertaking what is impure and practicing bad conduct that one attains purity, then that which is itself bad and impure being able to make another pure is unreasonable. Furthermore, is it through internal purity that one is ultimately pure, or through external purity that one is ultimately pure? If through internal purity, then attaining purity by bathing in river water is unreasonable. If through external purity, then [leaving] the interior full of defilement and confusion while only removing external dirt is unreasonable.