大般涅槃經義記 2.154

2.154

〈如來性品〉者，此品之中備論多法。「二十五有有我不」下一段經文辯如來性，今從彼文以題品目，蓋乃攝廣從略名矣。如來之藏能為佛因名如來性，廣辯斯義名〈如來性〉。於此品中備答多問。〈四相〉一章答前問中願開微密，廣為生說。准六卷經，前問略少，若具為問，應言「願佛開於微密，菩薩依之為眾生說」，故此文中「佛就涅槃微密藏中開三事義，令菩薩說」以答上問。此明何義？今此為顯無礙辯因，無礙辯才由為眾生說法故得，故此辯之。

As for the chapter “Tathāgata-Nature,” within this chapter many dharmas are fully discussed. From the section of sūtra text from “Do the twenty-five realms of existence have a self or not?” downward, the Tathāgata-nature is distinguished; taking from that text to entitle the chapter is simply gathering the broad under the brief to name it. The tathāgatagarbha, being able to serve as the cause of buddhahood, is called the Tathāgata-nature; distinguishing this meaning at length is called “Tathāgata-Nature.” Within this chapter, multiple questions are fully answered. The section on the four marks answers the previous question, “May [the Buddha] reveal the subtle and secret, and widely speak it for sentient beings.” According to the six-fascicle sūtra, the previous question was brief; if asked in full, it should say: “May the Buddha reveal the subtle and secret, and may bodhisattvas rely on it to speak for sentient beings.” Therefore, in this text, “The Buddha, regarding the subtle and secret treasury of nirvāṇa, reveals the meaning of the three matters, causing the bodhisattvas to speak,” answers the above question. What meaning does this clarify? Now, this is to reveal the cause of unobstructed eloquence; because unobstructed eloquence is attained through preaching the Dharma for sentient beings, it is therefore distinguished here.