大比丘三千威儀 1.57

1.57

著三法衣有五事：一者著泥洹僧，上無中尼衛，不得著安陀會；二者著中尼衛，上無安陀會，不得著欝多羅僧；三者著安陀會，上無欝多羅僧，不得著僧伽梨；四者三衣當令中外等；五者不得過三色。如法行步，是為道法。

There are five matters regarding wearing the three Dharma robes: first, wearing the nivāsana, without an inner garment above, one must not put on the antarvāsas; second, wearing the inner garment, without the antarvāsas above, one must not put on the uttarāsaṅga; third, wearing the antarvāsas, without the uttarāsaṅga above, one must not put on the saṃghāṭī; fourth, the three robes must be made even inside and out; fifth, they must not exceed three colours. Walking in accordance with the Dharma—this is the method of the Way.