大乘起信論義記 3.488

3.488

修習觀者，當觀一切世間有為之法，無得久停須臾變壞，一切心行念念生滅，以是故苦。應觀過去所念諸法恍惚如夢，應觀現在所念諸法猶如電光，應觀未來所念諸法猶如於雲歘爾而起。

"One who cultivates contemplation should contemplate that all conditioned phenomena of the world do not remain long and change and disintegrate in an instant, and that all mental activities arise and cease from thought-moment to thought-moment, and are therefore suffering. One should contemplate that all phenomena reflected upon in the past are fleeting like a dream; one should contemplate that all phenomena reflected upon in the present are like lightning; one should contemplate that all phenomena reflected upon in the future are like clouds suddenly arising."