Only when the manas personally realizes it is it true wisdom

Where is the master of the house when there is no dreaming and no thinking? This is the content of the third gate of Chan. Regardless of whether one has broken through the first or second gate, this content cannot be taught in detail or explained; otherwise, it will fall onto the level of the conscious mind—merely intellectual understanding—and it will become very difficult for the manas to realize it, which would render studying Buddhism and investigating Chan meaningless. Only after passing through the first and second gates, cultivating meditative concentration (samādhi) to attain the first dhyāna, and realizing the mirage contemplation, can one reach the third gate of Chan and begin investigating the third gate. At this point, one must all the more not seek others' explanations; passing through this gate makes one a non-returner (Anāgāmin). Whatever requires investigation requires the manas itself to personally investigate and personally realize it. If one merely hears it spoken by others, realization becomes impossible, and the Buddha-Way can no longer be cultivated any further.

If one investigates and brings forth the content of the third gate oneself, and also understands some of the theoretical knowledge of Yogācāra, one can enter the first bhūmi. But the gate of the first dhyāna will probably stump everyone. In the past, I still harbored the hope that someone might cultivate the first dhyāna, eliminate afflictions, and break through the obstruction of ignorance, thereby gaining a certain qualification to enter the first bhūmi and become a true son of the Buddha. Now it seems there is no such hope. Nowadays, cultivating meditative concentration in this world is so difficult because the five desires and six sense objects are too alluring. In truth, it is that people are too attached to the five desires and six sense objects. Sense objects have no mind to glue themselves to people, yet people have the mind to chase after sense objects. No one is willing to settle the mind and depart from the five desires—what can be done about it?

As for the first gate—"Who drags this corpse around?"—if this conclusion were made public, even if you knew who it is that drags the corpse, it would be of no use. You would still not know exactly how the corpse is dragged, and thus you could not attain enlightenment. If you do not personally investigate, if the manas does not resonate with it, then even knowing all the answers, knowing the most detailed answer, knowing the realm of the Buddha, is of no use whatsoever. If it were useful, we could all just read the Buddhist sutras, research out the realm of Buddhahood, and all of us together quickly attain buddhahood—wouldn't that be wonderful? In fact, what we know is not what we realize; knowing is easy, realization is hard. Knowing that all dharmas are dreams, illusions, bubbles, and shadows—does that mean one has already realized that all dharmas are dreams, illusions, bubbles, and shadows? Does knowing the realm of Buddhahood make one a Buddha? Neither is so. If an ordinary being understands and can describe the realm of cultivation of an arhat (the fourth fruit), does that mean he has the attainment of an arhat? If an ordinary being can describe how to accomplish the Buddha-Way, has he already become a Buddha? Neither is so.

To sum up: for many dharmas, it is useless for the conscious mind to easily know, understand, and comprehend them. One must still rely on the manas to personally realize them. Only through realization can there be the wisdom of liberation and the attainment of buddhahood. Without realization, even if one speaks with dazzling eloquence, it is utterly useless—one cannot attain liberation.