大乘起信論略述 2.220

2.220

論。修習觀者至須臾變壞　述曰。次辨觀。於中有四。一法相觀。二大悲觀。四精進觀。初中有四。一無常。二諸苦。三無我。四不淨。此觀於無常倒也。顯世間法迅速無常故。說有須臾變等。

[Treatise:] One who cultivates insight [... in a moment changes and decays]. [Exposition:] Next is discerning insight. Within this there are four: first, contemplation of dharmalakṣaṇa; second, contemplation of great compassion; third, contemplation of vows; fourth, contemplation of vigor. In the first there are four: first, impermanence; second, suffering; third, non-self; fourth, impurity. This contemplates the inversion of permanence. Showing that worldly dharmas are swift and impermanent, it speaks of "in a moment changes," and so forth.