大毘盧遮那成佛經疏 2.5

2.5

經云「內我」者，有計身中離心之外別有我性，能運動此身作諸事業。難者云：「若如是者，我即無常。何以故？若法是因及從因生，皆無常故。若我無常，則罪福果報皆悉斷滅。」如是等種種論義，至挍量中廣明。

The sūtra says: “An internal self.” There are those who impute that within the body, apart from the mind, there is a separate nature of the self, which is able to move this body and perform all activities. The refuter says: “If it is so, the self is impermanent. Why is that? Because if a dharma is a cause or produced from a cause, all are impermanent. If the self is impermanent, then the retribution of sin and merit would all be cut off.” Such various arguments will be explained at length in the appraisal section.