四分律刪繁補闕行事鈔 1.479

1.479

夫靜處思微，道之正軌；理須假日追功，策進心行。隨緣託處，志唯尚益；不許駝散，亂道妨業。故律通制三時，意存據道；文偏約夏月，情在三過：一無事遊行，妨修出業。二損傷物命，違慈寔深。三所為既非，故招世謗。以斯之過，教興在茲。然諸義不無，指歸護命故。夏中方尺之地，悉並有蟲，即《正法念經》云：夏中除大小便，餘則加趺而坐。故知護命為重，佛深制之。必反聖言，罪在不請；結業自纏，永流苦海。極誡如此，依文敬之。

Now, contemplating subtleties in a quiet place is the proper course of the Path; logically, one must use the designated days to pursue achievements and spur on the mental practice. Entrusting oneself to a place according to conditions, one's aspiration values only spiritual benefit; one is not permitted to wander in laxity, disturbing the Path and hindering one's practice. Therefore, the Vinaya generally establishes [retreats during] three seasons, the intention being to base oneself in the Path; the text specifically focuses on the summer months, with concern regarding three faults: first, wandering about without business hinders the practice of the transcendent path; second, harming living beings is truly contrary to compassion; third, since what is done is improper, it incurs worldly censure. Because of these faults, the teaching arose here. Although various meanings are present, the principal aim is to protect life. During the summer, in a space of a single square foot, there are insects everywhere; as the Saddharmasmṛtyupasthāna-sūtra states: In the summer, except for defecating and urinating, one otherwise sits cross-legged. Thus we know that protecting life is paramount, and the Buddha strictly instituted it. If one opposes the holy words, the guilt lies in being without invitation; karmic formations will entangle oneself, flowing forever in the sea of suffering. The utmost admonition being like this, respect it according to the text.