The originally pure mind of sentient beings， usually characterized as being immutable. In East Asian Maha^ya^na Buddhism， the mind-nature is usually interpreted as being equivalent to the Buddha-nature （citta-dharmata^）. This term can is used extensively in a number of major Maha^ya^na scriptures such as the Nirvana Sutra 涅槃经， Sutra of Perfect Enlightenment 圆觉经， and Huayan jing 华严经， but appears with even more frequency in the works of commentators such as Wonhyo 元晓， Fazang 法藏， Zhiyi 智顗， etc.