Oṁkāra exhibited the three original sounds of the alphabet — A, U and M. These three, O most eminent descendant of Bhṛgu, sustain all the different threefold aspects of material existence, including the three modes of nature, the names of the Ṛg, Yajur and Sāma Vedas, the goals known as the Bhūr, Bhuvar and Svar planetary systems, and the three functional platforms called waking consciousness, sleep and deep sleep.