釋迦譜 1.66

1.66

曇無德律云。鼓師摩。彌沙塞律云。欝摩一懿欝。此三音相近。以音而推。竊謂懿摩是正。但鼓懿字相似。故傳寫謬為鼓耳。

The Dharmaguptaka Vinaya says *Gushīma, and the Mahīśāsaka Vinaya says *Umā. I, Iṣ, and U—these three sounds are close. Deducing from phonetics, I humbly think that *Iṣīma is correct. It is merely that the characters gu (鼓) and yi (懿) are similar, so scribal transmission mistakenly made it gu.