瑜伽論記 7.117

7.117

答中有四：一者、行苦壞苦唯聖知，苦苦愚亦覺，故自聲說；二者、苦苦極可厭患；三、纔說苦苦則便領易；四、可化有情聞說易入於諦。

In the answer there are four points: first, the suffering of conditioned existence and the suffering of change are known only by the noble ones, whereas the suffering of suffering is felt even by the foolish, hence it is spoken of with its own term; second, the suffering of suffering is utterly repulsive; third, as soon as the suffering of suffering is spoken, it is easily grasped; fourth, sentient beings who can be transformed, upon hearing it spoken, easily enter the truths.