大般涅槃經義記 7.219

7.219

不壞樂中，先列其名，生死法中破壞名苦，是故涅槃不壞名樂。「身若壞」下釋彼不壞以為樂義，先反後順，「以大樂」下將義顯體，成涅槃大。

In the bliss of indestructibility, it first lists its name: within the dharmas of birth and death, destruction is called suffering, therefore the non-destruction of nirvāṇa is called bliss. From "if the body is destroyed" downward explains non-destruction as constituting the meaning of bliss, first negatively and then positively; from "by great bliss" downward uses the meaning to reveal the substance, establishing the greatness of nirvāṇa.