In the MahāparinirvāNa Sūtra found authoritative expositions of numerous doctrines central to spiritual practice in Mahāyāna Buddhism, including permanence, eternity, tranquility, and incorruptibility, the understanding and cultivation of which brings insight into the key principle of emptiness (śūnyatā). However, even a thorough understanding of all these doctrines, when limited to the intellectual level, is not conducive to spiritual development; what this requires is the systematic application of these doctrines in such a way that one’s experience of oneself and the world are fundamentally and permanently transformed. Inasmuch as the MahāparinirvāNa Sūtra provides a definitive teaching on nirvāNa, its primary purpose coincides with that of the Āgama and Prajñāpāramitā sūtras—to serveas a guide to spiritual practice.