大般涅槃經義記 1.36

1.36

自下第二聲光召新，先聲後光，音聲是語，表召分明，故先出之。「二月十五日」者，出聲時也。垂滅曰臨，晨朝出聲，後夜當滅，去滅不遙，故曰臨也。此說化滅以為涅槃，又復息化歸真亦名涅槃。

From here down, the second part is the voice and light summoning the new [assemblies], first the voice and then the light. A voice is speech, which signifies and summons clearly; therefore it is emitted first. “The fifteenth day of the second month” is the time the voice was emitted. Being on the verge of extinction is called “approaching”; emitting the voice in the early morning, he was to enter extinction in the latter part of the night. Because it was not far from extinction, it is called “approaching.” This refers to the extinction of the manifestation as nirvāṇa; furthermore, ceasing the manifestations and returning to the real is also called nirvāṇa.