大般涅槃經義記 6.12

6.12

Question: In the preceding treatment of internal, external, and so forth, there was a threefold division of separation and combination; why is this not the case here with conditioned and unconditioned dharmas? Explanation: Analytically establishing it would also not do harm to the principle, but here, in order to clarify that the two dharmas, internal and external, are both existent, combining them in contemplation is easy; therefore the third is the collective contemplation of internal and external. Conditioned and unconditioned differ in status as existence and non-existence, so combining them in contemplation would be difficult; hence there is no collective [contemplation].