大般涅槃經義記 1.149

1.149

就難身中文具有三，一彰昔異今，「先受施者是雜食身」，約緣辯身；「煩惱身」者，約因辯身，從煩惱生，生煩惱故。「是後邊身、無常身」者，當相辯身，後邊簡前，生死之窮，故曰後邊；無常異後，遷機未息，故名無常。二明今異昔，「後受施者無煩惱身」，翻前煩惱。「金剛」別論，非是翻前，其身難壞，故如金剛。「法身」翻前雜食之身，諸功德法集成佛身，故名法身。常翻無常，無邊翻邊。

With respect to the objection concerning the body, the text completely possesses the three [parts]: first, revealing how the past differed from the present: "the one who previously received the giving was a body of coarse food" distinguishes the body in terms of conditions; "an afflicted body" distinguishes the body in terms of cause, as it is born from afflictions and generates afflictions. "A final body and an impermanent body" distinguishes the body in terms of its direct characteristics: "final" distinguishes it from the previous, being the culmination of birth and death, and therefore is called "final"; "impermanent" differs from the subsequent, as the mechanism of change has not ceased, and therefore it is called "impermanent." Second, clarifying how the present differs from the past: "the one who subsequently received the giving has an unafflicted body" inverts the preceding "afflicted." "Vajra" is discussed separately and does not invert the preceding: because that body is difficult to destroy, it is like vajra. "Dharmakāya" inverts the preceding body of coarse food: because all dharmas of merit are gathered to form the Buddha's body, it is called the dharmakāya. "Permanent" inverts "impermanent"; "boundless" inverts "bounded" (final).