大般涅槃經義記 7.198

7.198

問曰：下說二乘涅槃但有樂、淨而無我、常，今此文中何故異彼？解云：二乘說佛涅槃同己所得，有寂滅樂，謂佛滅後同己灰盡，無覺知樂，故言無樂。大乘說彼小乘涅槃終須遷轉，又所滅心當必還生，故曰無常。小乘謂己所得涅槃究竟永寂，將己所得類佛涅槃，故說為常。

Question: Below it is said that the nirvāṇa of the two vehicles has only bliss and purity, but lacks self and permanence; why does it differ from that in this passage? Explanation: The two vehicles say that the Buddha's nirvāṇa is identical to what they themselves have attained, possessing the bliss of quiescence, and they claim that after the Buddha's extinction it is just like their own reduction to ashes, lacking the bliss of awareness; hence it is said to lack bliss. The Mahāyāna says that their Hīnayāna nirvāṇa must ultimately undergo transformation, and furthermore that the extinguished mind must necessarily arise again; hence it is called impermanent. The Hīnayāna claims that the nirvāṇa attained by itself is ultimate and eternally quiescent, and assimilates its own attainment to the Buddha's nirvāṇa; hence it is said to be permanent.