釋氏要覽 3.381

3.381

攝大乘論云。有三種。一念念壞滅無常。二和合離散無常。三畢竟如是無常○唯識疏釋。無常有二義。一有生滅體是無常。二無他常故名無常。

The Mahāyānasaṃgraha states: There are three kinds: first, impermanence of moment-by-moment disintegration; second, impermanence of combination and dispersion; third, impermanence of ultimately being such. The Weishi shu explains: Impermanence has two meanings: first, that which has arising and ceasing is in its substance impermanent; second, it is called impermanent because it lacks other permanence.