What does it mean that the manas internally grasps the Ālayavijñāna as self?

This means that the manas grasps the functions and operations of the Ālayavijñāna as its own functions and operations, without knowing that these are the functions and operations of the Ālayavijñāna. Following along with the dharmas perceived by the Ālayavijñāna, it takes these dharmas to be the self and what belongs to the self, not knowing that they are produced by the Ālayavijñāna, belong to the Ālayavijñāna, and are in essence all of the nature of the Ālayavijñāna. Therefore, the manas craves and clings to the functions and operations of the Ālayavijñāna, delights in the functions and operations of the Ālayavijñāna, takes pleasure in the functions and operations of the Ālayavijñāna, and grasps at the functions and operations of the Ālayavijñāna. Because of these graspings and craving attachments, the manas is bound and cannot attain liberation, and thus there is birth and death that cannot be relinquished. The manas fundamentally does not know what dharma the Ālayavijñāna is, so it is not grasping at the Ālayavijñāna itself; rather, it mistakenly believes that all the functions produced by the Ālayavijñāna are its own functions, and that all dharmas belong to itself, and thus grasping arises.

What are the functions and operations of the Ālayavijñāna? Nothing other than the functions and operations of the five aggregates and eighteen realms, nothing other than the functions and operations of all worldly dharmas. The manas takes all these functions and operations to be the self and what belongs to the self. This misunderstanding only begins to be gradually dissolved after one realizes the Ālayavijñāna. When the manas realizes the Ālayavijñāna, it will, together with the mind consciousness, come to observe that the functions and operations of the five aggregates and eighteen realms are all produced by the Ālayavijñāna, are the functions and operations of the Ālayavijñāna, and are not the functions and operations of the manas-self; thus the grasping of self is gradually eradicated. Then, as one successively realizes that all other dharmas are likewise the functions and operations of the Ālayavijñāna and not the functions and operations of the manas-self, the grasping of dharmas is gradually eradicated, ignorance is gradually exhausted, and one accomplishes the supreme nirvāṇa and attains great liberation.

Animals all have the grasping of self and the grasping of dharmas—which of them can know that there is an Ālayavijñāna? They merely take those functions produced by the Ālayavijñāna, those dharmas that are born forth, to be their own. What the manas grasps is only those dharmas produced by the Ālayavijñāna—how could it be grasping at the Ālayavijñāna itself? Studying the Dharma is not about dissecting words; one cannot circle around on the literal surface, but must deeply engage in contemplative practice (vipaśyanā-caryā) on its profound meaning and ultimate meaning. Most people's study of the Dharma consists only of shallow intellectual deliberation by the mind consciousness; they never cultivate meditative concentration (samādhi) to think deeply and contemplate. That is why so many people cultivate and study the Hīnayāna teachings of suffering, emptiness, impermanence, and non-self, yet in the end arrive at the conclusion that the five aggregates are not the eighth consciousness and yet are not different from the eighth consciousness—a conclusion that is not even logically coherent. What ordinary being would ever hold the notion that the five aggregates are the eighth consciousness? Anyone who holds this notion is no longer an ordinary being, and would not need to engage in contemplative practice to eradicate the view of self (satkāya-dṛṣṭi) or to personally realize the eighth consciousness at all.