注維摩詰經 7.166

7.166

[Kumāra]jīva says: The devas put various famous medicines into the ocean and grind them with precious mountains to produce amṛta; eating it, they become immortals, and it is called the medicine of immortality. In the Buddha-Dharma, using the amṛta of nirvāṇa, saṃsāra is permanently severed; this is the true medicine of immortality. It is also said that at the beginning of the kalpa there was the taste of the earth, amṛta, eating which gave long life. In the Buddha-Dharma, the amṛta of the true mark nourishes one's wisdom-life; this is the true food of amṛta.
[Dao]sheng says: The food of devas has the flavor of amṛta; eating it brings longevity, hence it is named the food of immortality. Nirvāṇa is the dharma of immortality, therefore it is used as a metaphor.