Yogācārabhūmi Śāstra, Volume 34 (42)

Original text:依外别离无常性者。谓现前有资生财宝。先未变异。未为别离无常灭坏。后时为王盗贼。非爱及共财等之所劫夺。或由恶作加行失坏。或方便求而不能得。如是等类应知。是名由别离行知无常性。

Explanation: Relying on the impermanence of external separation means that one presently has wealth and treasures that support one's livelihood, which previously had not undergone change—the treasures had not yet been separated, had not yet perished through impermanence—but later they were confiscated by the king, stolen by thieves, plundered by those who are not dear to one, or lost and dissipated as another's common property; or they were ruined through forceful and violent action, or one could no longer obtain them even when seeking them by convenient means. From these phenomena one should know—this is called knowing the nature of impermanence through the conduct of separation.