(Sanskrit, literally "fourth") The fourth and highest of the four states of consciousness, transcending the states of vigil ("wakened"), dreaming, and deep sleep. The state of turiya is described in the Mandukya Upanishad as "Invisible, otherworldly, incomprehensible, without qualities, beyond all thoughts, indescribable, the unified soul in essence, peaceful, auspicious, without duality, is the fourth stage, that self, that is to be known." In other words, this is the point of view of Atman / Chesed. "The fourth state is without parts and entanglements; Not bound to this world, It is auspicious and non-dual. Thus the form of AUM is verily the Self itself. He who knows thus enters into his own Self by himself."
"The yogī who places his mind in My form of Nārāyaṇa, known as the fourth factor [turīya-ākhye], full of all opulences, becomes endowed with My nature and thus obtains the mystic perfection called vaśitā." - Śrīmad Bhāgavatam 11.15.16