淨名經集解關中疏 2.263

2.263

The Bodhisattva Priyadarśana said, "Form and the emptiness of form constitute duality. Form is emptiness itself; it is not that the extinction of form is emptiness, but that the nature of form is inherently empty. In this way, feeling, perception, karmic formations, consciousness, and the emptiness of consciousness constitute duality. Consciousness is emptiness itself; it is not that the extinction of consciousness is emptiness, but that the nature of consciousness is inherently empty. To thoroughly penetrate this is entering the dharma gate of non-duality."
Form is obstruction; the extinction of form is emptiness—this is duality. If one realizes that the nature of form is inherently empty, then emptiness and form are non-dual. Sengzhao says, "If existence does not equal emptiness, non-existence cannot wipe out its traces. The remaining aggregates should be understood accordingly."