注維摩詰經 3.161

3.161

肇曰：愧其所犯，不敢問佛，以優波離持律第一故從問也。疑其所犯不知輕重，悔其既往廢亂道行，故請持律解免斯咎也。生曰：違禁誠重，能改為貴，是以許有改法也。優波離解律第一，故以問焉。疑者恐罪及己，而猶有不至之異也。悔者既已懼之，必自悔所為也。

[Seng]zhao says: "Ashamed of their violation, they dared not ask the Buddha; since Upāli was foremost in upholding the Vinaya, they came to ask him. Doubting their violation, they did not know whether it was light or grave; regretting what had past, they were ruining and disordering their practice of the Path. Therefore, they requested the Vinaya-holder to resolve it and exempt them from this fault." [Dao]sheng says: "Violating prohibitions is indeed grave, but being able to reform is prized; therefore methods of repentance are permitted. Upāli was foremost in understanding the Vinaya, hence they questioned him. Those who 'doubt' fear sin falling upon them, yet retain differences in whether it applies. Those who 'regret', having already feared it, must naturally repent what they did."