Adhyatma Upanishad is a minor Upanishad assigned to Sukla_Yajur_Veda. Adyatma Upanishad start with search in the one aja (unborn) which is located anywhere. It is in the cave of the body. Earth is his body, though he pervade in Earth, it does not know him. Water is his body, though he pervade in Water, it does not know him. Agni is his body, though he pervade in Agni, it does not know him. Akasa is his body, though he pervade in Akasa, it does not know him. Mind is his body, though he pervade in Mind, it does not know him. Buddhi is his body, though he pervade in Buddhi, it does not know him. Mrtyu is his body, though he pervade in Mrtyu, it does not know him. He, who is inner soul of all creatures and purifier of sins, is the one divine Lord Narayana. By the practice of deep meditation, the “I and mine” in the body can be discovered as Atma which is same as Brahman. Atma is full, beginning-less, immeasurable, unchangeable, replete with sat, cit, ananda.

The end portion of the Upanishad says, this science was imparted to Apantaratama who gave it to Brahma. Brahma gave it to Ghora Angiras. Ghora Angiras gave it to Raikva, who gave it to Rama. And Rama gave it to all being.