瑜伽論記 6.42

6.42

又不淨想略有二種下，第二逐前難釋中分三：初、釋在家初不淨相；次、釋出家於無常所修苦想；三、釋遠離閑居中修光明想。不淨想，中有三：初、列二力；次、明二障；後、明除此能治法多有所作。

From 'Moreover, the perception of impurity is briefly of two kinds' downward, the second part, which pursues the preceding difficult explanations, is divided into three: first, explaining the first mark of impurity in the lay state; next, explaining the perception of suffering cultivated with respect to impermanence in the renunciant state; third, explaining the cultivation of the perception of light in secluded dwelling in solitude. In the perception of impurity, there are three parts: first, listing the two powers; next, explaining the two obstacles; last, explaining that the antidotal dharma eliminating these is greatly beneficial.