'knowledge of the Ultimate Reality')[1] is a branch of Hindu scriptural knowledge derived primarily through a study of the Upanishads,[2] the Brahma Sūtras, and the Bhagavad Gita.
Its cognates in other Indo-European languages are the Greek εἶδον for ἐϝιδον ("I saw"), οἶδα for ϝοιδα ("I know"), Latin vidēre ("to see"), Slavic věděti, Gothic ("witan, wait"), Germanic wizzan, wissen ("to know"), and the English ("wisdom, wit").
The Shatapatha Brahmana features a legend in which the sage Atharvan was threatened decapitation by Indra if he restored the head of a sacrifical offering, since it would lead to the revelation of esoteric knowledge.
When Indra duly carried out this decapitation after the revelation, the Ashvins promptly restored the real head of the sage.
[7] In modern Hinduism, Brahmavidya is used to mean a spiritual study of Hindu scriptures with the aim of realising the Ultimate Reality.