The Difference Between the Buddha's Nirvāṇa and the Arhat's Nirvāṇa

There is an essential difference between the Buddha's nirvāṇa and the arhat's nirvāṇa. After the Buddha's nirvāṇa, He still manifests countless five-aggregate bodies to deliver sentient beings in worlds throughout the ten directions; therefore the Buddha says the five-aggregate body is called liberated form (mokṣa-rūpa). When the Buddha's conditions for delivering sentient beings in one world have come to an end, He extinguishes the physical body, and this is conventionally called nirvāṇa. For example, when Śākyamuni Buddha entered nirvāṇa in the Sahā world, His physical body temporarily departed and was extinguished, yet Śākyamuni Buddha remains the Dharma lord, teaching master, and guide of the Sahā world, and the sentient beings of the Sahā world are still disciples under Śākyamuni Buddha's teaching and transformation. At the same time, Śākyamuni Buddha manifests immeasurable and boundless five-aggregate bodies in worlds throughout the ten directions to teach and transform sentient beings in those ten directions. After an arhat's nirvāṇa, there will no longer be any physical body or five aggregates, so after an arhat's nirvāṇa there is no liberated form (mokṣa-rūpa); their nirvāṇa is one of lack of self-mastery (avaśatā), and their liberation is not thorough.

The Buddha has the five aggregates, yet He is liberated; His liberated form (mokṣa-rūpa) can be seen by sentient beings with the naked eye and is not bound by any dharma of the world. Although sentient beings also have the five aggregates, they are bound by worldly dharmas and therefore cannot attain liberation. When the mind is liberated, the physical body is liberated, and all five aggregates are liberated. Therefore liberation does not necessarily require extinguishing the physical body and the five aggregates; rather, one must extinguish the mind-states and views that are not in accord with reason and the Dharma. When one's mind-states are transformed into views and understanding that accord with reason and reality, one is liberated.