俱舍論記 20.13

20.13

「由契經中至勤斷欣求」者，答。經中既說過去色有勤修厭捨，未來色有勤斷欣求，明知過去、未來實有。觀色無常，於過去色能勤修厭捨。又解：觀無常故名勤修厭，不顧戀故名勤修捨。觀色無常，於未來色能斷欣求，欣求即是緣未來色貪。又解：觀無常故名勤斷欣，不希欲故名勤斷求。

Regarding "Because in the sūtras ... diligently sever desire and craving": this is the reply. Since the sūtras state that because past form exists one diligently cultivates aversion and renunciation, and because future form exists one diligently severs desire and craving, one clearly knows that past and future are substantially existent. Contemplating the impermanence of form, one can diligently cultivate aversion and renunciation toward past form. Another explanation: contemplating impermanence is called "diligently cultivating aversion"; not yearning back is called "diligently cultivating renunciation". Contemplating the impermanence of form, one can sever desire and craving toward future form; desire and craving are greed directed toward future form. Another explanation: contemplating impermanence is called "diligently severing desire"; not hoping for or longing after is called "diligently severing craving".