大般涅槃經義記 4.310

4.310

現病品者，向前為病人皆謂實，此品廣明如來無病，方顯前病應現為之，名〈現病品〉。此品兩請備如向判，然今迦葉先請如來止其病言，後佛因之身現無病。

As for the "Chapter on Manifesting Sickness": previously, when he became sick, all people supposed it was real; this chapter extensively clarifies that the Tathāgata has no sickness, thereby revealing that the previous sickness was manifested in response [to beings]; hence it is called the "Chapter on Manifesting Sickness." The two requests in this chapter are fully as analyzed previously; however, here Kāśyapa first requests the Tathāgata to cease speaking of his sickness, and afterward the Buddha, in response to this, manifests no sickness in his body.