大般涅槃經義記 1.69

1.69

問曰：現觀人類不多，今此何故獨優婆塞有其二恒，餘眾漸多？釋言：今此三千同聚，故有二恒。又隨報別，一處之中有多種人，斯皆雲集，故有二恒。如《法華》中「眾生見劫盡，大火所燒時，天人常充滿」，如是等也。

Question: Observing the human species at present, they are not numerous. Why do the upāsakas alone here number two Gaṅgās[' sands], while the remaining assemblies gradually increase? Answer: Here, [those of] the three thousand [great thousand worlds] gather together, and therefore there are two Gaṅgās[' sands]. Furthermore, according to differences in retributions, within a single place there are many kinds of persons, all of whom gather like clouds, and therefore there are two Gaṅgās[' sands]. This is like in the Lotus Sūtra: "When sentient beings see the end of the kalpa and all is consumed by a great fire, [this land of mine is peaceful,] always filled with devas and humans," and so forth.