法界次第初門 2.133

2.133

苦諦下四行：一、無常行者，觀五受陰因緣生，新新生滅，故無常也。二、苦行者，觀五受陰若無常即是苦，為無常之所逼也。三、空行者，觀五受陰一相、異相無故空，即是空。四、無我者，觀五受陰中我、我所法不可得故無相，是為無我行也。

The four aspects under the truth of suffering: 1. The aspect of impermanence: contemplating that the five appropriated skandhas arise from causes and conditions, being newly born and extinguished moment by moment; hence they are impermanent. 2. The aspect of suffering: contemplating that if the five appropriated skandhas are impermanent, they are suffering, being oppressed by impermanence. 3. The aspect of emptiness: contemplating that because the five appropriated skandhas lack a single characteristic or distinct characteristics, they are empty; this is emptiness. 4. The aspect of non-self: contemplating that within the five appropriated skandhas, a self and what belongs to a self are unattainable and therefore markless; this is the aspect of non-self.