四分比丘戒本疏 2.41

2.41

第九、無有智男子與女說法過五六語戒。「五六語」者，五六科也。如五蘊為五科，六根為六科，廣釋五六科並未是犯。若其傍有有智男子為第三人識別染淨，不限多少也。《多論》第六必是白衣男子，若出家人不得以事同故。若准此律，下文有寶對夫開第四人，不對開第三人，及與女露坐開第三人。律文並云「若有二比丘為伴不犯。」准即不同《多論》也。

Ninth: the precept against teaching the Dharma to a woman for more than five or six sentences in the absence of a discerning man. 'Five or six sentences' refers to five or six categories. For instance, the five aggregates are five categories, and the six sense-bases are six categories; explaining five or six categories extensively does not yet constitute an offence. If there is a discerning man alongside as a third party who distinguishes between purity and defilement, there is no limit on the amount. The sixth fascicle of the Sarvāstivāda-śāstra states that he must be a white-robed layman; if he is a monastic, he cannot [serve as the witness], because their circumstances are the same. If we follow this Vinaya, below, in the presence of valuables facing a husband, a fourth person is permitted, not facing [the husband] a third person is permitted, and for sitting in the open with a woman a third person is permitted. The texts of the Vinaya all say: 'If there are two monks as companions, it is not an offence.' Accordingly, this differs from the Sarvāstivāda-śāstra.