宋高僧傳 11.27

11.27

系曰：商那和脩，華言胎衣也，以其生帶衣而誕，以繒肉而非，幼為繃褓，長且稱身；出家成法服，至入滅闍維，方為煨燼焉。晟師之有胎衣，止不及為嬰兒已往之服耳，此近叔離尼、商那尊者也，思過半矣。何邪？晟師去聖懸遠，和修佛滅百年將胎衣示有行果之徒也，今晟以胞袒絡化其教理之世，不其難乎！故曰思過半矣。

The appraisal states: Śāṇavāsa means in Chinese 'linen robe'; because he was born wearing a caul, which was treated as silk and not flesh, it served as swaddling clothes in infancy and fit his body as he grew; when he left home it became a monastic robe, and only when he entered extinction and was cremated did it turn to ashes. Master Cheng's possessing an amniotic caul merely fell short of continuing as his garment after infancy, yet he was close to the Venerables Śuklā and Śāṇavāsa; he was more than halfway there. Why is this? Master Cheng was far removed from the sage: Śāṇavāsa, a hundred years after the Buddha's nirvāṇa, displayed the amniotic caul to disciples with fruit of practice, while Cheng today converted this age of doctrinal understanding with his shoulder-baring caul—is this not difficult indeed? Therefore, it is said that he was more than halfway there.