四分比丘戒本疏 2.74

2.74

The forty-fourth precept: This refers to a household of the food of lustful desire where there is a husband capable of treasuring [his wife]; although the husband is not present, the monk sits in a screened place beyond the reach of an outstretched hand from the doorway, so that outsiders cannot see them; therefore he commits an offence. If there is a third person, he commits no offence.