梵網經菩薩戒本疏 6.124

6.124

四、具緣者，此中制五種行：一、頭陀，二、遊方，三、坐禪，四、安居，五、布薩。皆具四緣：一、為修行，二、知是難，三、不遠避，四、故入中，便犯也。

Fourth, regarding the fulfillment of conditions: five types of practices are prescribed here: first, dhūta; second, wandering abroad; third, sitting in meditation; fourth, the rains retreat; fifth, poṣadha. All possess four conditions: first, being for cultivation; second, knowing it is dangerous; third, not avoiding it from afar; fourth, intentionally entering it. Then an offense is committed.