大般涅槃經義記 3.316

3.316

就初段中，如來初先略言，起發迦葉啟請，後佛偈答。前中四句：第一如來彰經深重明如甘露亦似毒藥、二迦葉請、三如來試問欲知藏不、四迦葉請。就初句中，言「如甘露亦如毒」者，於信能益故如甘露、於謗能損故似毒藥。道此何為？三歸真性由經趣入，故說甘露令人信樂，明是毒藥使人捨謗。此義未顯，故第二請如來「何緣說方等經譬如甘露復以毒藥」。欲求祕藏，須知樂不？故第三問「欲知藏不」。彼聞欣踊，故第四請，云「我欲知」。

Regarding the first section, the Tathāgata first speaks briefly to induce Kāśyapa's inquiry, and then the Buddha answers in verse. In the former there are four phrases: first, the Tathāgata reveals that the sūtra is profound and grave, explaining that it is like ambrosia and also like poison; second, Kāśyapa requests; third, the Tathāgata tests with a question whether he wishes to know the treasury or not; fourth, Kāśyapa requests. In the first phrase, saying "it is like ambrosia and also like poison": for faith it can benefit, hence it is like ambrosia; for slander it can harm, hence it is like poison. Why speak of this? The true nature of the three refuges is entered through the sūtra; therefore he speaks of ambrosia to cause people to have joyful faith, and explains it is poison to cause people to abandon slander. This meaning was not yet manifest, so second he asks the Tathāgata, "For what reason do you say that the vaipulya sūtras are like ambrosia and also like poison?" Wanting to seek the secret treasury, one must know whether he delights in it or not; hence third he asks, "Do you wish to know the treasury or not?" Hearing it, he leapt with joy, hence fourth he requests, saying, "I wish to know."