大般涅槃經義記 4.184

4.184

下明自德，即是答上云何捨死如蛇脫皮；今明如來隨化示滅，其實不死，故如蛇矣。文中有二：一明如來如蛇脫皮，其實不死，正答上問；二「如金師」下乘明如來得實起用，體常不變。前中四句：第一如來立喻反問、二迦葉正答、第三如來舉法反問、四迦葉正答，文顯可知。後中先喻，「金師」喻佛，「得好真金」喻得真實緣起法身，「作種種器」喻起化身。次合顯法，「如來亦爾」合前金師，「於二十五」下合作諸器。初先正合，「為化」已下辨真化意。「是故」下結，「雖復示現，常住不變」合好真金。

Below, [the text] clarifies his own virtue; that is, answering the above question: "How does one shed death like a snake sloughing its skin?" Here it clarifies that the Tathāgata, in accord with [the needs of] conversion, manifests extinction, but in truth does not die; thus he is like a snake. Within this text there are two parts: first, clarifying that the Tathāgata is like a snake sloughing its skin and in truth does not die, which directly answers the previous question; second, from "Just as a goldsmith..." onward, drawing upon [the simile] to clarify that the Tathāgata attains the real and gives rise to function, while his essence is eternally unchanging. In the former part there are four phrases: first, the Tathāgata sets up the simile and poses a counter-question; second, Kāśyapa answers directly; third, the Tathāgata adduces the Dharma and poses a counter-question; fourth, Kāśyapa answers directly; the text is evident and can be understood. In the latter part, first the simile: "the goldsmith" is a simile for the Buddha; "obtains fine, pure gold" is a simile for attaining the true conditioned dharmakāya; "fashions various vessels" is a simile for giving rise to the transformation bodies. Next comes the matching to reveal the Dharma: "The Tathāgata is also like this" matches the preceding goldsmith; from "in the twenty-five [existences]..." downward matches fashioning the various vessels. First it matches directly; from "for the sake of transforming..." onward it explains the meaning of true [essence] and transformations. Below, "For this reason..." concludes: "although he manifests [transformations], he is eternally abiding and unchanging" matches the fine, pure gold.