俱舍論記 10.217

10.217

「世尊於此至何謂三聚」者，此下就有情世間中大文第二明三聚別。問：世尊於此有情世間初生、次住、後沒三時中建立三聚，何謂三聚？又解：生謂生有、住謂本有、沒謂死有、中謂中有，於此四種建立三聚。聚顯眾多有情，何謂三聚？

Regarding "Here the World-Honoured One ... what are the three groups?": below this, within the sentient world, the second major section clarifies the distinction of the three groups. Question: The World-Honoured One establishes three groups within the three periods of initial birth, subsequent abiding, and final decease of this sentient world; what are the three groups? Another explanation: Birth refers to birth-existence, abiding refers to basic existence, decease refers to death-existence, and intermediate refers to intermediate existence; within these four, the three groups are established. "Group" indicates a multitude of sentient beings; what are the three groups?