四分比丘戒本疏 2.58

2.58

第二十七、二十八期行期同船。律云「先不共期，道路相遇，畏慎不敢共行。佛言：不期無犯。」

Twenty-seventh and twenty-eighth: traveling by appointment and boarding a boat by appointment [with a bhikṣuṇī]. The vinaya states: 'If they did not make an appointment beforehand, but encountered each other on the road, and out of apprehension and caution dared not travel together, the Buddha said: "If there is no appointment, there is no offence."'