The Bodhisattva Mahamati requested the Buddha's instructions on the way to cultivate the path of the bodhisattva.
The Buddha answered, "Mahamati, the bodhisattva cultivates the path by practicing the four ways
"The first is to see that all that exists appears from the mind. The three realms of existence cannot exist independent of the mind.
"The realms originate from one's idea of 'I' and 'mine.' They are never in a state of going or coming, but because of enduring habits, which developed a long time ago, they appear as the three realms.
"Thus we must see that all things that exist, actions, words, bondage, the human body, treasures, or places of residence are all the results of discriminations.
"The second is to discard thoughts on arising, abiding, and perishing and to see that all is like a dream. This is because there is nothing that came into being by itself, nor is there anything created by another.
"Furthermore, nothing comes about through itself and others. Things are the creations of one's mind, and they have no substance. Now, if there is no substance in external things, the discriminating mind cannot be aroused. Knowing that it is only by discrimination that the three realms exist, there is nothing inwardly or outwardly, to grasp. All is like a dream, devoid of arising, abiding, and perishing. The bodhisattva, upon realizing this, is freed from the ideas of arising and perishing.
"The third is to contemplate on the absence of self-nature among external objects. One perceives all things to be like a mirage or dream. One perceives that all things owe their existences to worthless arguments, a variety of attachments, and deluded habits, and that originally and in actuality, all things are without a substantive nature.
"The fourth is to view all that exists in this manner and to seek the highest wisdom."
The Bodhisattva Mahamati then asked the World-Honored One about the nature of nirvana.
To this the Buddha responded, "The state of nirvana is attained by overturning the delusive feeling that fills the self-nature of the unenlightened mind, the habitual forces of the alaya-vijnana (the seventh ego-grasping consciousness), and one's mind. This realm is identical with that state in which a person realizes that the very nature of all that exists is characterized by emptiness and is also identical with the sacred wisdom free from the categories of cessation of existence, everlasting existence, existence, and nonexistence.
"Furthermore, there is no disintegration in nirvana, nor is there death. Suppose there were such a thing as death; then we must suppose that there is birth. If there is such a thing as disintegration, that means that things change. Nirvana is where there is no disintegration and no death; it is the realm where all who culitvate the path will arrive. Nirvana does not discard the dharmas in the mundane world; it is neither identical with the mundane dharmas nor different from them."
The Bodisattva then asked the Buddha what the basis was of the World-Honored One's contention regarding the truth of permanence.
To this the World-Honored One answered, "Mahamati, the realm of the everlasting Dharma can be explained by things in the realm of unenlightenment, which is ruled by the law of impermanence.
"Illusory dharmas also appear in the same way to the eyes of the sages, but the sages observe them in their true light. The unenlightened tend to view matters such as shimmering heat waves, fire rings, mirages, dreams, illusions, or reflections in a mirror in an inverted way; but the wise look at them correctly. These delusions are basically set apart from existence and nonexistence and thus are not impermanent. For instance, for the hungry devil, it would be impossible to say that there is water here because he does not see the river Ganges. On the other hand, because others can see the river, they cannot say there is no water here. Now in regard to all things that exist in the realm of delusion, originally there is neither existence nor nonexistence, and therefore they are said to exist eternally.
"Although there should be no distinctions among things, because of a person's perception distinctions are recognized; in truth, however, their essential nature is eternal existence. Mahamati, all that exists, though in the state of delusion, is true as it is. The sage does not consider things perverted although he may reside in the realm characterized by illusory existence. The illusory dharmas are, at the same time, real dharmas. If and when his subjective ego-consciousness mind is activated in his observations, then he is no longer a sage."
The Bodhisattva Mahamati then asked the Buddha whether all illusory existences were existing or nonexisting.
The World-Honored One answered, "To adhere to either existence or nonexistence is an indication of attachment. Actually, all things that exist are originally set apart from such attachments and are threrefore said to exist in a dream. If, however, all existences possess their own substance and do not undergo change, then these would be what the believers of other teachings call atman. However, all things that exist come about because of countless conditions and therefore undergo change; for this reason I say that the existences in the world of delusions are existences in the process of undergoing change."
The Bodhisattva Mahamati then asked the Buddha, "You say that the existences in the world of delusion are identical with illusions. If this is so, can they become the cause of other existences in the world of delusion?"
To this the World-Honored One answered, "Mahamati, illusory existences cannot become the causes of other existences in the world of delusion. This is because illusory existences cannot become the causes of errors. In other words, illusory existences cannot exercise calculation and for this reason cannot bring about miscalculations. Through attachment to things the ignorant create illusion, but the sages free themselves from attachment and see the truth in temporary existences.
"If there were to be a a truth besides transitory existence, then that truth would become also a part of temporary existence. Mahamati, by the nirvana that I speak of, I mean the annihilation of the sixth consciousness which is the mind that falsely discriminates phenomnena in the plane of temporary existence."
Dialogue between the Buddha and Bodhisattva Mahamati
Source -Buddha Dharma – The Way to Enlightenment - Numata Center for Buddhist Translation 2003