大般涅槃經義記 7.88

7.88

上來法說，次以喻況，於中還四，先喻初段明大涅槃本有非今，「闇室」喻於眾生之身，「井及七寶」喻涅槃法，「人亦知者」寄知顯有，「闇故不見」喻前第二惱覆不見，「有智人」下喻上第三，「是人於此終不念」下喻上第四。

The above was the exposition of the dharma; next is the illustration by analogy, wherein there are likewise four. First is the analogy for the first section, clarifying that the great nirvāṇa is originally existent and not newly arisen: the "dark room" illustrates the body of sentient beings; the "well and seven treasures" illustrate the dharma of nirvāṇa; "a person also knows it" borrows knowledge to reveal existence; "not seen because of darkness" illustrates the second [section] above, being covered by defilements and not seen; from "a wise person" downward illustrates the third above; from "this person never thinks in this regard" downward illustrates the fourth above.