The Meaning of “Perfect Illumination Gives Rise to an Object; Once an Object Is Established, the Nature of Illumination Perishes” in the Śūraṅgama Sūtra

The perfect, luminous, and wondrous bodhi light shines upon the dharma realm that He gives birth to. If someone takes this dharma realm as truly existent, as a real and indestructible dharma, as self or as belonging to self, then it is like a single leaf blocking the eye—one sees the false and not the true, and fails to see the radiance of the wondrous luminous true mind of the fundamental essence, the self-nature. Thus birth and death flow on without cease.

Write words on a blackboard with a piece of chalk—what are those words? They are all chalk dust. If you only recognize the words and not the chalk, the chalk dust is obscured. The chalk is a metaphor for the self-natured pure mind, the perfect wondrous luminous true mind; the chalk dust is a metaphor for the self-nature's luminosity; the words on the blackboard are a metaphor for worldly dharmas; and the blackboard is a metaphor for the worldly realm.