瑜伽師地論略纂 8.36

8.36

論「各有中衣，若有下衣」者，述曰：中衣即殟呾羅僧伽，先云欝多羅僧伽也，亦云七條。今云中衣，在大衣下，五牒上，名中衣；亦名中擁，能擁身而處中故。下衣即五牒也，最在此下故。重辨三衣之法。又衣有中、下，故名中、下衣。若爾，何故無上衣？明知此中三衣為論，上衣即僧伽胝也。

Regarding the treatise's "each having an intermediate robe, or having a lower robe": The commentary says: The "intermediate robe" is the uttarāsaṅga—formerly called yutuoluosengjia—also called the seven-strip robe. Now it is called the "intermediate robe": below the great robe and above the five-strip robe, it is called the intermediate robe; it is also called the "intermediate wrapper," because it wraps the body and occupies the middle. The "lower robe" is the five-strip robe, because it is lowermost beneath this. This re-articulates the rules of the three robes. Furthermore, robes have intermediate and lower, hence they are called the intermediate and lower robes. If so, why is there no upper robe [mentioned here]? One clearly knows that the discussion here is about the three robes, and the upper robe is precisely the saṃghāṭī.