The Buddha’s Mahaparinirvana
Yesterday was the 15th day of the second lunar month, the Buddha’s Mahaparinirvana Memorial Day in Chinese Buddhism.
Nirvana, also translated as "extinction" (灭度) or "perfect tranquility" (圆寂), means the complete eradication of afflictions and liberation from the suffering of birth and death. "Extinction" (灭度) refers to the cessation of afflictions and the transcendence of the sea of suffering, while "perfect tranquility" (圆寂) signifies the fulfillment of all merits and the complete eradication of afflictions. As stated in the Infinite Life Sutra (Amitāyus Sūtra): "In this world, the Buddha appears to enter extinction."
The Tathāgata's Dharma body (法身) is eternal—how could there be birth and death? However, to guide countless sentient beings to realize the truth of impermanence (in this Samsaric world), the Buddha deliberately demonstrated entering Parinirvana (般涅槃) to awaken beings and help them detach from the suffering of impermanence.
The Nirvana Sutra (Mahāparinirvāṇa Sūtra) states:
"If one sees the Buddha-nature and can sever afflictions, this is called Mahāparinirvāṇa."
Nirvana is a state of being—a state of complete fulfillment, free from any afflictions. It is not directly related to life and death. Many people believe that when the Buddha left this world, it was Parinirvana. However, this is merely a demonstration for ordinary beings. To great Bodhisattvas, the Buddha has never truly left this world, nor has he ever "arrived" in it.
Why is that? Because the Dharma body (法身) is eternal—it neither comes nor goes. The meaning of Tathagata means the thus come one - AS IT IS.
Then why did the Buddha appear in this world? It was simply a manifestation according to conditions (随缘现相), appearing in this world at a particular time to inspire sentient beings who have the karmic affinity to be awakened at that moment.
The Buddha's demonstrated departure from the world was to awaken beings of lesser capacities in later generations. But what is the true state of Nirvana? It is the state of "eternity, joy, Self (True Self= Buddha nature), and purity" (常乐我净)—a state where "tranquility is bliss" (寂灭为乐). The Tathāgata had already eradicated all afflictions long ago, so there is no need for him to attain eternal peace through any other means.
You can watch a video in which Jiawen discusses the Buddha’s Mahaparinirvana here: