Indivisibility of samsara and nirvana
The indivisibility of saṃsāra and nirvāṇa (Tib. འཁོར་འདས་དབྱེར་མེད་, Wyl. 'khor 'das dbyer med) is to hold the indivisibility, or equality, of samsara and nirvana in the dharmata devoid of inherent existence. It is the main formulation of the view of the Sakya School of Tibetan Buddhism.
External Links
Short explanation of the indivisibility of samsara and nirvana by Gatön Ngawang Lekpa