四分律比丘含注戒本 2.730

2.730

尼同犯。不犯者：有三根，若說實令悔，不誹謗；若戲，若錯說者。

Bhikṣuṇīs commit the same offense. As for non-offenses: there are the three grounds [seen, heard, suspected]; or if one speaks the truth to cause him to repent and does not slander him; or if done in jest, or if spoken mistakenly.