勅修百丈清規 5.38

5.38

蓋法衣有三也。一僧伽黎（即大衣也）二欝多羅僧（即七條也）三安陀會（即五條也。此是三衣也。若呼七條偏衫裙為三衣者非也）又三品大衣（上品二十五條。二十三條。二十一條。中品十九條。十七條。十五條。下品十三條。十一條。九條）田衣緣起。僧祇律云。佛住帝釋石窟前。見稻田畦畔分明。語阿難云。過去諸佛衣相如是。從今依此作衣相。增輝記云。田畦貯水生長嘉苗。以養形命。法衣之田潤以四利之水。增其三善之苗。以養身法慧命也。

There are three Dharma robes: first, the saṃghāṭī (that is, the great robe); second, the uttarāsaṅga (that is, the seven-strip robe); third, the antarvāsas (that is, the five-strip robe. These are the three robes; it is incorrect to call the seven-strip robe, the side-seamed jacket, and the skirt the three robes). There are also three grades of the great robe (the upper grade has twenty-five strips, twenty-three strips, or twenty-one strips; the middle grade has nineteen strips, seventeen strips, or fifteen strips; the lower grade has thirteen strips, eleven strips, or nine strips). The origin of the field robe: the Mahāsaṃghika Vinaya says that when the Buddha was staying before the rock cave of Śakra, he saw the dikes and borders of the rice fields clearly demarcated, and said to Ānanda, 'The robes of past Buddhas had such an appearance; from now on, make the appearance of robes in accordance with this.' The Zenghui Ji says: 'The dikes of fields store water to grow fine sprouts and nourish bodily life; the fields of the Dharma robe are moistened with the water of the four benefits to increase the sprouts of the three goods, thereby nourishing the body of the Dharma and the life of wisdom.'