大般涅槃經集解 51.52

51.52

案僧亮曰：默無所說便是涅槃者，答初難也。寶亮曰：此下答第一難，明魔王不識涅槃之真體。謂佛直爾默然不說法，便是涅槃也。

Sengliang comments: That remaining silent and saying nothing is precisely nirvāṇa answers the first objection. / Baoliang comments: From here on answers the first objection, clarifying that the Demon King did not recognize the true substance of nirvāṇa. He thought that the Buddha simply being silent and not expounding the Dharma was precisely nirvāṇa.