When can one finally achieve non-discriminative grasping of marks?

Only after attaining the first fruit and eliminating self-view (ātma-dṛṣṭi) can one break through the marks of self, of persons, of sentient beings, and of a life span; yet one still cannot avoid grasping at and discriminating the marks of sentient beings' five aggregates (pañcaskandha). Even after enlightenment, refraining from grasping at marks is extremely difficult—especially after meditative concentration (samādhi) has regressed, for the vast majority of the time one still must grasp at marks and discriminate them. Bodhisattvas before the eighth bhūmi simply cannot achieve complete non-grasping and non-discrimination of marks. Ordinary beings (pṛthagjana) cannot withstand even the smallest test; no matter how they train themselves not to be attached to marks or to grasp at marks, ordinary beings inevitably revolve within marks. Although ordinary beings often say with their own mouths that they will not grasp at marks and discriminate, every single minute they are grasping at marks and discriminating—they simply cannot manage not to grasp at marks or not to discriminate. 

Because their meditative concentration and wisdom realization are severely insufficient, wanting to refrain from grasping at marks and discriminating is simply impossible. The mind consciousness may forcibly suppress it for one minute, perhaps, but by two minutes it can no longer hold out. Not grasping at marks and not discriminating is extremely, extremely difficult to accomplish. Thinking about it is easy, and talking about it is easy too, but to actually accomplish it, one must realize that all marks are unreal. Only as much as one has realized can one accomplish; thinking is useless, and verbal talk is even more useless. Even if an ordinary being cultivated for another countless kalpa, it would be hard to say to what degree they could refrain from grasping at marks and discriminating. Arhats likewise cannot achieve complete non-grasping and non-discrimination of marks, because arhats have not realized the Mahāyāna Dharma, and therefore they inevitably have to grasp at marks and discriminate. If arhats could refrain from grasping at marks and discriminating, they would not grasp at the suffering of the Sahā world and single-mindedly seek to escape the realms of the Sahā world to enter nirvāṇa without remainder (anupadhiśeṣa-nirvāṇa).