Eternal Buddha in Mahayana Buddhism

In some sutras found in Mahayana Buddhism, the Buddha teaches that the Buddha is no longer essentially a human being but has become a being of a different order altogether and that, in his ultimate transcendental "body/mind" mode as Dharmakaya, he has eternal and infinite life, is present in all things (i.e., is "the boundless dharmadhatu", according to the Nirvana Sutra), and is possessed of great and immeasurable qualities. In the Mahaparinirvana Sutra the Buddha declares: "Nirvana is stated to be eternally abiding. The Tathagata [Buddha] is also thus, eternally abiding, without change." This is a particularly important metaphysical and soteriological doctrine in the Lotus Sutra and the Tathagatagarbha sutras. According to the Tathagatagarbha sutras, failure to recognize the Buddha's eternity and - even worse - outright denial of that eternity, is deemed a major obstacle to the attainment of complete awakening (bodhi).
For the Tibetan Buddhist master, Dolpopa, and his Jonangpa School, the Buddha is to be understood as the wondrous and holy wish-fulfilling Essence of all things, beyond comprehension:
"Buddha - an essence of immeasurable, incomprehensible, unfathomable, excellent exalted body, wisdom, qualities, and activities extremely wondrous and fantastic - is vast like space and the holy source, giving rise to all that is wished by sentient beings like a wish-granting jewel, a wish-granting tree …" (Dolpopa, Mountain Doctrine, tr. by Jeffrey Hopkins, Snow Lion Publications, 2006, p. 424).