瑜伽論記 1.438

1.438

故俱舍云：從世間初成十九別劫，於無量時已度此，無量壽眾生漸減乃至十歲，世間已成及住，是住初別劫。

Therefore the Abhidharmakośa states: 'From the initial formation of the world through nineteen separate kalpas; after having passed this immeasurable time, the lifespan of these immeasurable sentient beings gradually decreases down to ten years: the world has already formed and dwells; this is the first separate kalpa of dwelling.'