諸經要集 2.10

2.10

又十誦律云。有五種人。問法皆不應為說。一試問。二無疑問。三不為悔所犯故問。四不受語故問。五詰難故問。並不得答。若前人實有好心。不具前意。為欲生善滅惡者。法師隨機方便好心為說。若自解未明。或於法有疑者。則不得為說。恐令前人有錯傳之失。彼此得罪。

Furthermore, the Daśabhāṇavāra-vinaya states: 'There are five kinds of people to whom the Dharma should not be preached when they ask: first, those who ask to test; second, those who ask without doubt; third, those who ask not for the purpose of repenting an offense; fourth, those who ask with no intention of accepting instruction; fifth, those who ask to interrogate and find fault. To all of these one must not respond. If the person truly has a good mind, does not possess the aforesaid intentions, and wishes to give rise to good and eradicate evil, the Dharma master should preach for him with a good mind, adapting to the occasion through skillful means. If one's own understanding is not yet clear, or if one has doubts about the Dharma, one must not preach it, for fear of causing the other person to receive an erroneous transmission, so that both parties commit an offense.'