Bumping this thread with this important Upanishad. Mandukya Upanishad is the shortest of all Upanishads and has only 12 verses. It describes the sound "AUM" as the primordial sound that created the whole universe. A represents the waking state or Gross State(Vaishvaanara), U represents dreaming state or Subtle State (Taijasa), and deep sleep state (Prajnya). These three states are attained through vibration (manifested form of the divine) and we are all part of it. We move between one state to another every day throughout our lives. When we stop this vibration momentarily by silencing this vibration, we can feel the communion with the divine existence. But those who aspire to dwell in the fourth stage that is also called "Turiya State" or infinite consciousness which is formless, attributeless, and inconceivable will have to transcend the mind that manifests the three Gunas.