俱舍論記 2.97

2.97

「如是已說至外謂此餘」者，此下第十六內外門。泛明內外略有三種，故《婆沙》一百四十八云「然內外法差別有三：一相續內外，謂在自身名內，在他身及非情數名為外。二處內外，謂心、心所所依名內，所緣名外。三情、非情內外，謂有情數法名內，非情數法名外。」今此論中約處內外。心名為我，是我依根，即名為內，故言十二。外謂此餘色等六境，非我依故。雖諸根、識亦通所緣，約處以明，所依常定，但名為內；不據為境，名為外也。

Regarding "Having thus explained... the external refers to the remaining ones": below is the sixteenth section, the category of internal and external. In general, explaining internal and external briefly comprises three kinds; hence Vibhāṣā 148 says: "However, the distinction between internal and external factors is threefold: First, the internal and external of continuum, meaning that what is within one's own continuum is called internal, while what is in other continua and non-sentient things is called external. Second, the internal and external of bases (āyatana), meaning that the supports of mind and mental factors are called internal, while the objects of cognition are called external. Third, the internal and external of sentient and non-sentient, meaning factors belonging to sentient beings are called internal, while factors belonging to non-sentient things are called external." Now in this treatise, it is according to the internal and external of bases. The mind is called "self"; the faculties that are the supports of this self are called internal; hence it says twelve [are internal]. The external refers to the remaining ones, namely the six objective fields such as form, because they are not supports of the self. Although the faculties and consciousnesses also extend to being objects of cognition, explaining them according to the bases, as supports they are always determined [as such] and thus are called solely internal; they are not called external on the basis of being objects.