Yogācārabhūmi Śāstra, Volume 34 (30)

Original text: 云何观察乘事变异无常之性。谓于一时见种种乘。新妙庄严。甚可爱乐。复于一时见彼朽故。离诸严饰。见此事已。便作是念。如是诸行。其性无常。余如前说。云何观察衣事变异无常之性。谓由观见种种衣服。一时新成。一时故坏。一时鲜洁。一时垢腻。见此事已。便作是念。如是诸行。其性无常。余如前说。

Explanation: How does one contemplate the impermanent nature of change in vehicle matters (yāna-vastu)? At one time, one sees various vehicles still new, wondrous, and adorned, very delightful and lovable; at another time, one sees those vehicles decayed and worn, no longer beautiful or adorned. Having observed these phenomena, one then has this thought: such conditioned formations are truly impermanent in their nature. How does one contemplate the impermanent nature of change in clothing matters? One sees various garments—at one time newly made, at another time old and worn out; at one time fresh and clean, at another time covered with dirt and grime. Having observed these phenomena, one then has this thought: such conditioned formations are truly impermanent in their nature.