四分律刪繁補闕行事鈔 1.493

1.493

二明得法有緣不來。《四分》：受七日出界，為父母兄弟姊妹本二私通等，至意留之，過日不來，得歲。若鬼神等，水陸道斷、盜賊、虎狼諸難，同前得成。準此，難靜即還反界；因即停止，破夏。《僧祇》：夏中受日和僧，道行不得迂迴，直道而去；至彼，中前和了，中後即還。若停住者，準即破夏。

Second, explaining valid procedure where one does not return due to conditions: The Dharmaguptaka Vinaya states: Taking seven days to leave the boundary on account of father, mother, brothers, sisters, former spouses, etc., who detain him with sincere intention, if he exceeds the days and does not return, he obtains the monastic year. If there are distresses such as spirits and deities, severed water or land routes, bandits, or tigers and wolves, it is validly accomplished as before. Accordingly, as soon as the distress subsides, he must return to the boundary; if he takes the opportunity to linger, he breaks varṣā. The Mahāsāṃghika-vinaya states: When taking days during the summer to harmonize the Saṅgha, one's route of travel must not be circuitous, but one must go by the straight path; arriving there, if harmonized before noon, one immediately returns in the afternoon. If one lingers, accordingly it breaks varṣā.