Mahāyāna Mahāparinirvāṇa Sūtra
The sutra is remarkable for the vigor and passion with which Aṅgulimālīya teaches the Dharma and for its doctrine that at the heart of all beings is one unified principle: the "buddha-dhatu" (Buddha-nature) or "Tathāgatagarbha". The doctrines of this sutra are also strikingly congruent with those of the much longer "Mahāyāna Mahāparinirvāṇa Sūtra".