瑜伽論記 6.429

6.429

解三衣中，三衣則用好疊判成。僧伽胝者此當有上義，謂入王宮聚落此衣最在上被，故有上義，具足應言僧伽胝婆參，婆參衣。

In explaining the three robes, the three robes are determined using fine cloth. *Saṅghāṭī* here has the meaning of 'upper': when entering royal palaces and settlements, this robe is worn topmost, hence it has the meaning of 'upper'; fully stated, it should be *saṅghāṭī-vāsana*, *vāsana* meaning robe.