大般涅槃經義記 1.48

1.48

自下第二明其舊眾覩相增悲。云何知此是前舊眾？文不說來，故知舊眾；下簡未集，不簡此眾，故知是舊。以是舊故，六卷經中全無此文。

From here below, the second section explains that the old assembly, beholding the signs, experienced an increase in sorrow. How do we know that these are the former, old assembly? The text does not say they “came,” so we know they are the old assembly. Below, where those who had not yet assembled are selected, this assembly is not selected, so we know they are the old assembly. Because they are the old assembly, this passage is entirely absent from the six-fascicle sūtra.