“One should continuously worship Brahman with the Syllable Om. For thus it is said, ‘This Syllable indeed, is holy, this Syllable indeed is supreme. By knowing that Syllable indeed, whatever one desires becomes his.’ And then it has been said elsewhere, ‘This Om is the sound form of this [Self].’ Therefore by the utterance of the Syllable Om all these forms [of Brahman] are praised, worshipped, and ascribed. For thus it is said: ‘This Syllable Om, verily, is the higher and lower Brahman.’” (Maitri Upanishad 6:4,5)
“‘I am that Om alone, having been freed from every other thing.’ This [realization] results from meditation on Om, as well as the knowledge of the nature of Brahman.” (Shandilya Upanishad 6:32)
