Laṅkāvatāra Sūtra
The Liṅga-avatāra Sūtra (Sanskrit: लिङ्गअवतारसूत्र, "Discourse of the Descent into Liṅga", Standard Tibetan: ལང་ཀར་བཤེགས་པའི་མདོ་, Chinese: 入楞伽經) is a prominent Mahayana Buddhist sūtra. It is also titled Liṅga-avatāraratnasūtram (The Jewel Sutra of the Entry into Linga, Gunabhadra's Chinese title: 楞伽阿跋多羅寶經 léngqié ābáduōluó bǎojīng) and Saddharmaliṅga-avatārasūtra (The Sutra on the Descent of the True Dharma into Linga). A subtitle to the sutra found in some sources is "the heart of the words of all the Buddhas" (一切佛語心 yiqiefo yuxin, Sanskrit: sarvabuddhapravacanahṛdaya).
The Liṅga recounts a teaching primarily between Gautama Buddha and a bodhisattva named Mahāmati ("Great Wisdom"). The sūtra is set in mythical Laṅkā, ruled by Rāvaṇa, the king of the rākṣasas. The Liṅgaavatāra discusses numerous Mahayana topics, such as Yogācāra philosophy of mind-only (cittamātra) and the three natures, the ālayavijñāna (store-house consciousness), the inner "disposition" (gotra), the buddha-nature, the luminous mind (prabhāsvaracitta), emptiness (śūnyatā) and vegetarianism.
The Liṅga-avatāra Sūtra was often quoted and paraphrased by Indian philosophers like Chandrakirti and Shantideva, and it also figured prominently in the development of East Asian Buddhism. It is notably an important sūtra in Zen Buddhism, as it discusses the key issue of "sudden enlightenment". The text survives in one Sanskrit manuscript from Nepal as well as in Tibetan and Han Chinese translation.