Mandukya Upanishad The Māṇḍūkya Upaniṣad, the shortest yet one of the most profound Upaniṣads of the Atharva Veda, consists of just twelve mantras but presents a complete philosophy of the Self and ultimate reality. It explains the sacred syllable Om as the symbol of Brahman and the Self, mapping it onto the four states of consciousness: waking (jāgrat), dreaming (svapna), deep sleep (suṣupti), and the transcendent fourth state (turīya), which is pure awareness beyond dualities. While the first three states correspond to the ordinary experiences of embodied beings, turīya is described as unchanging, infinite, and the true essence of the Self. The Upaniṣad emphasizes that realization of this turīya, through meditation on Om and inner inquiry, leads to liberation, making it a cornerstone text for Advaita Vedānta and the philosophy of non-duality.

Mundaka Upanishad The Muṇḍaka Upaniṣad, belonging to the Atharva Veda, is a poetic and philosophical text that distinguishes between higher knowledge (para vidyā), which leads to realization of Brahman, and lower knowledge (apara vidyā), which concerns rituals and worldly learning. It teaches that Brahman is the eternal, imperishable reality, while the world of names and forms is transient, like sparks from a fire. Using powerful imagery, it describes the Self as the two birds on a tree—one eating the fruits (the individual soul) and the other silently witnessing (the supreme Self)—and proclaims that liberation comes not through ritual but through meditation, renunciation, and direct knowledge of Brahman. The Upaniṣad also introduces the famous image of Brahman as the higher reality into which all beings and the universe dissolve, affirming that true immortality lies only in realizing the Self.