俱舍論記 16.24

16.24

「論曰至故名牟尼」者，釋上兩句無學身、語業及意，名三牟尼。非以意業為牟尼體。所以者何？勝義牟尼唯心為體，其相難顯，由身、語業離眾惡故，可以比知。有比用故，說身、語業亦名牟尼。意思既非勝義，復無比用，不名牟尼。故《正理》云「此心牟尼，由身、語業離眾惡故，可以比知。意業於中無能比用，唯能、所比合立牟尼（已上論文）。」又身、語業是遠離戒體，能離眾惡，戒名遠離。意業不然，無無表故，非遠離體。由遠離惡義建立牟尼，故即心由身、語業能有所離，故名牟尼。

Regarding "The treatise says: ... hence they are called muni": This explains the upper two lines: the aśaikṣa bodily and vocal karmas and the mind are called the three munis. It is not that mental karma constitutes the essence of muni. Why is this? The ultimate muni has only the mind as its essence; its characteristics are difficult to manifest, but because bodily and vocal karmas are free from various evils, it can be known through inference. Because they have inferential utility, bodily and vocal karmas are also said to be called muni. Mental cetanā, being neither ultimate nor possessing inferential utility, is not called muni. Thus the Nyāyānusāra says: 'This mental muni, because bodily and vocal karmas are free from various evils, can be known through inference. Mental karma has no inferential utility therein; only the combination of what is inferred and the means of inference is established as muni' (end of treatise passage). Furthermore, bodily and vocal karma are the essence of the morality of renunciation, capable of avoiding various evils; morality is termed renunciation. Mental karma is not so: lacking avijñapti, it is not the essence of renunciation. Since muni is established on the basis of renouncing evil, the mind, by means of bodily and vocal karma, can effect renunciation and is therefore called muni.