Mandukya_Upanishad

8. This identical Ātman, or Self, in the realm of sound isthe syllable OM, the above described four quarters ofthe Self being identical with the components of thesyllable, and the components of the syllable beingidentical with the four quarters of the Self. Thecomponents of the Syllable are A, U, M.jāgarita-sthāno vaiśvānaro’kāraḥ prathamāmātrā’pter ādimattvād vā’pnoti ha vaisarvān kāmān ādiś ca bhavati ya evaṁ veda.9. Vaiśvānara, whose field is the waking state, is the firstsound, A, because this encompasses all, and because it isthe first. He who knows thus, encompasses all desirableobjects; he becomes the first.svapna-sthānas taijasa ukāro dvitīyāmātrotkarṣāt ubhayatvādvotkarṣati ha vaijñāna-saṁtatiṁ samānaś ca bhavatināsyābrahma-vit-kule bhavati ya evam veda.10. Taijasa, whose field is the dream state, is the secondsound, U, because this is an excellence, and contains thequalities of the other two. He who knows thus, exalts13