成唯識論述記 10.268

10.268

述曰：緣苦、集行流轉相為障，執有染是，相多現行，即障緣起還滅觀，緣滅道淨相為障。

The Commentary states: Taking the active marks of the transmigration of suffering and origin as an obstacle constitutes grasping at the existence of defilement, which is an active manifestation of many marks; this obstructs the contemplation of the cessation of conditioned origination, wherein taking the pure marks of cessation and the path as an obstacle [constitutes grasping at purity].