Chandogya Upanishad, one of the primary Upanishads has been written during the Vedic Brahmana period. It is related to the Sama Veda and consists of eight chapters. Many references have been made in the Brahma sutras from this Upanishads. The 23rd Khanda of Second Chapter of Chandogya Upanishad states about the praise of Om Mantra that is not associated with any ritual. According to dharma have three divisions, study, sacrifice and charity. These belong in the first category. The second is the austerity. The third is to reside in the abode of a teacher as a brahmacharin, and mortify the body there. One achieves the worlds of the honourable who practise these dharmas. However, one achieves immortality who is able to establish himself in the supreme Brahman. The world is being brooded over by Prajapati. The threefold knowledge was revealed within the heart. He provided the syllables, Bhuh, Bhuvah and Svah. He then dwelled on these syllables from which evolved the Om Mantra.

This article is a stub. You can enrich by adding more information to it. Send your Write Up to content@indianetzone.com