If you use your mind to study reality, you won't understand either your mind or reality. If you study reality without using your mind, you'll understand both.
But people of the deepest understanding look within, distracted by nothing. Since a clear mind is the Buddha, they attain the understanding of a Buddha without using the mind.
If you see your nature, you don't need to read sutras or invoke buddhas. Erudition and knowledge are not only useless but also cloud your awareness. Doctrines are only for pointing to the mind. Once you see your mind, why pay attention to doctrines?
The mind's capacity is limitless, and its manifestations are inexhaustible. Seeing forms with your eyes, hearing sounds with your ears, smelling odors with your nose, tasting flavors with your tongue, every movement or state is all your mind.
When your mind doesn't stir inside, the world doesn't arise outside. When the world and the mind are both transparent, this is true vision. And such understanding is true understanding.