天台八教大意 1.7

1.7

These four flavors, in contrast to the sudden, are called gradual. The Saddharmapuṇḍarīka and the Nirvāṇa are not subsumed under either the sudden or the gradual; they open the preceding sudden and gradual and unite them into the buddha vehicle. In terms of the sequence of the metaphor, it is called the flavor of ghee. Therefore the Nirvāṇa [Sūtra] says: 'From the Mahāprajñāpāramitā emerges the Mahāparinirvāṇa, united with the Saddharmapuṇḍarīka, just as from clarified butter comes the flavor of ghee.' Therefore Kāśyapa expressed his understanding, saying: 'When his end approached, he summoned his son,' and so forth; this is the fifth flavor.