In Hinduism, the water of life or nectar of immortality is called “amrita” (“immortal”). It is frequently employed in the Vedas (cf. “soma”), but is also part of Śivaite Tantra, where it is coupled with “rakta” (“blood”) and its associated sacrificial practices.
In the Sâdhana of Amitâyus (the Buddha of Boundless Life, a manifestation of Amitâbha, the Buddha of Boundless Light), the long-life vase containing the nectar of immortality (“amrita”) appears. It is employed in longevity rituals, aimed to increase the lifespan of practitioners with the intention to benefit sentient beings longer.
In the iconography of Padmasambhava, the long-life vase returns, but rests in the skull-cup (“kapila”), representing the polarity symbols of white & red “drops” essential in all Highest Yoga Tantras.
In Tantras of the Father (method) class, method is represented by the white drops situated in the crown wheel, and wisdom by the red drops in the navel wheel. The Lunar white drop (from the father) is linked with “amrita” and the “method” of the long-life vase, whereas the Solar red drop (from the mother) is “rakta” (“blood”) and the “wisdom” of the skull-cup (in Mother tantras, stressing wisdom, these polarities may be reversed). The white drops sustain the solid white organs of bone, brain, marrow & spinal cord, whereas the red drops gives rise to the soft red organs of viscera, blood & muscle tissue. These equivalences are not direct, but indirect by way of hylic-pluralistic multicorporality, in particular the subtle anatomy of the “Vajra body” with its “wheels” (“ćakra”), “channels” (“nadî”) & “winds” (“prâna” or “ch’i”).