This paper explores the concept of Cid-aditya Realization outlined in the Mahāvākya Upaniṣat, focusing on recognizing consciousness's source within oneself. While Samādhi traditionally marks the pinnacle of all yogic practices and the ultimate goal of yoga, the Upaniṣat assert Cid-aditya Realization to be the highest, surpassing esteemed achievements like yoga siddhis, Laya and even Samadhi. According to the Upaniṣat, this realization leads to understanding the unity between individual and universal consciousness, culminating in realizing the self as Sachidanand. This profound teaching is exclusively reserved for highly qualified seekers known as the Tivra-tara seekers. It precisely conveys that focusing on and understanding the essence of normal breathing, particularly the Ajapā Gāyatrī, can lead one to this realization. Those who attain this understanding perceive the phenomenal world as Brahman, while those who do not remain under the veil of ignorance known as Avidyā. The Upaniṣat unequivocally asserts that Cid-aditya Realization holds the utmost significance within the Mahāvākya Upaniṣat, which occupies a distinguished position as the Shirsha of the Atharva Veda. Consequently, grasping the conceptual essence of this teaching becomes imperative for all spiritual seekers.