A single of those Sanskrit Mahayana sutras, the Vimalakīrti Nirdeśa Sūtra contains a chapter about the "Dharma gate of non-duality" (advaya dharma dvara pravesa) which is claimed to be entered after a person understands how several pairs of reverse extremes are to be rejected as forms of grasping. These extremes https://www.facebook.com/NonDualTeachers/