大般涅槃経
According to the "Mahāyāna Mahāparinirvāṇa Sūtra" (also called the "Nirvana Sutra"), the Buddha taught that "parinirvāṇa" is the realm of the Eternal, Bliss, the Self, and the Pure. Dr. Paul Williams states that it depicts the Buddha using the term "Self" in order to win over non-Buddhist ascetics. However, the "Mahaparinirvana Sutra" is a long and highly composite Mahayana scripture, and the part of the sutra upon which Williams is basing his statement is a portion of the Nirvana Sutra of secondary Central Asian provenance - other parts of the sutra were written in India.