Then Mahamati asked the Blessed One, saying: What are the steps that will lead an awakened disciple toward the self-realization of Noble Wisdom? The Blessed One replied: The beginning lies in the recognition that the external world is only a manifestation of the activities of the mind itself, and that the mind grasps it as an external world simply because of its habit of discrimination and false-reasoning. The disciple must get into the habit of looking at things truthfully. He must recognize the fact that the world has no self-nature, that it is un-born, that it is like a passing cloud like an imaginary wheel made by a revolving firebrand, like the castle of the Gandharvas, like the moon reflected in the ocean, like a vision, a mirage, a dream. He must come to understand that mind in its essence-nature has nothing to do with discrimination nor causation; he must not listen to discourses based on the imaginary terms of qualifications; he must understand that Universal Mind in its pure essence is a state of imagelessness, that it is only because of the accumulated defilements on its face that body-property-and-abode appear to be its manifestations, that in its own pure nature it is unaffected and unaffecting by such changes as rising, abiding and destruction; he must fully understand that all these things come with the awakening of the notion of an ego-soul and its conscious mind.

(The Lankavatara Sutra)