Buddhist Tantras in the context of "Upadeśa"

Luminous mind (Skt: prabhāsvara-citta or ābhāsvara-citta, Pali: pabhassara citta; Tib: འོད་གསལ་གྱི་སེམས་ ’od gsal gyi sems; Ch: 光明心 guangmingxin; Jpn: 光明心 kōmyōshin) is a Buddhist term that appears only rarely in the Pali Canon, but is common in the Mahayana sūtras and central to the Buddhist tantras. It is variously translated as "brightly shining mind" or "mind of clear light", while the related term luminosity (Skt. prabhāsvaratā; Tib. འོད་གསལ་བ་ ’od gsal ba; Ch. guāng míng; Jpn. kōmyō; Kor. kwangmyōng) is also translated as "clear light" or "luminosity" in Tibetan Buddhist contexts or "purity" in East Asian contexts.

The Theravada school identifies the "luminous mind" with the bhavanga, a concept first proposed in the Theravāda Abhidhamma. The later schools of the Mahayana identify it with bodhicitta and tathagatagarbha. The luminosity of mind is of central importance in the philosophy and practice of the Buddhist tantras, Mahamudra, and Dzogchen.

The Vairocanābhisaṃbodhi Sūtra (Vairocana’s Awakening Sutra, Sanskrit: 𑀯𑁃𑀭𑁄𑀘𑀦𑀸𑀪𑀺𑀲𑀁𑀩𑁄𑀥𑀺𑀲𑀽𑀢𑁆𑀭), also known as the Mahāvairocana Tantra (Sanskrit: 𑀫𑀳𑀸𑀯𑁃𑀭𑁄𑀘𑀦𑀢𑀦𑁆; traditional Chinese: 大毘盧遮那成佛神變加持經; ; pinyin: Dà Pílúzhēnà Chéngfó Shénbiàn Jiāchí Jīng; also known as 大日經 Da Ri Jing) is an important Vajrayana Buddhist text composed before 674 CE. The Indian tantric master Buddhaguhya (fl. c.700 CE) classified the text as a caryātantra, and in Tibetan Buddhism it is still considered to be a member of the carya classification. In Japan where it is known as the Mahāvairocana Sūtra (Daibirushana jōbutsu jinpen kajikyō), it is one of two central texts in the Shingon school, along with the Vajrasekhara Sutra. Both are also part of the Tendai school.

Though the text is often called a tantra by later figures (including later Indian commentators), the scripture does not call itself a tantra.