大般涅槃經義記 3.66

3.66

下佛答中先答初問，「如有王」下答其後問。前中初言「我涅槃後四十年中廣行流布」明法興時。何因緣故此時偏興？佛滅度後，迦葉持法經二十年、阿難持法亦二十年，此之二人親覩佛化，行法似佛，故令法興。迦葉向前直問癈時，佛今為欲對興辨癈，故明興時。「然後乃當隱沒地」者明法癈時，當處不行故言沒地。「如甘蔗」下辨明向前興癈所由，人學故興、不學故癈，先喻後合。

In the Buddha's answer below, he first answers the first question; from "Just as there is a king" onward, he answers the subsequent question. In the former, he first says, "Within forty years after my nirvāṇa, it will be widely disseminated and circulated," explaining the time when the Dharma flourishes. For what cause and condition does it especially flourish at this time? After the Buddha's parinirvāṇa, Kāśyapa upheld the Dharma for twenty years, and Ānanda also upheld the Dharma for twenty years. These two people personally witnessed the Buddha's conversion and practiced the Dharma similarly to the Buddha; therefore, they caused the Dharma to flourish. Kāśyapa had previously asked directly about the time of abandonment; now, wishing to distinguish abandonment by contrast with flourishing, the Buddha explains the time of flourishing. "Thereafter it will sink into the earth" clarifies the time of the Dharma's abandonment; because it will not be practiced in that place, it is said to "sink into the earth." From "Just like sugarcane" onward explains the reason for the aforementioned flourishing and abandonment: because people study it, it flourishes; because they do not study it, it is abandoned; first is the analogy, and afterward the application.