The above statement and other Mahaavaakyas in Sanskrit are the ‘Great Sayings’ available in the Upanishads, the inexhaustible sources of the spiritual knowledge of ancient India. The focus of Upanishads is proclaiming the glory of Brahman, the Infinite Supreme Spirit, and thus they represent the Advaita Vedanta wing of Hindu Philosophy.
Aham Brahmasmi is from the ‘Brhadaaranyaka Upanishad’, a part of Yajur Veda, and it means ‘I Am Brahman’. Aham = I; and Brahmasmi = am Brahman. (This Brahman should not be confused with ‘Brahman’/’Brahmin’, the Hindu ‘upper’ caste). It implies ‘I am part of the reality’. Who coined the words, when and where? It is not known clearly. Indians are not known to keep records of their own history. What a loss! From Shankaracharya to Narayana Guru several thinkers and spiritual leaders have given commentaries on it. If we can have the realization that we are one with Brahman (reality), we can love each other and love all living and non-living beings. If I realize that you and I are part of Brahman, how can we hate or destroy each other? I am destroying myself when I attack the others. But what is Reality? How do you define ‘Real’?
The subject matter and the essence of all Upanishads being the same, all the Mahaavaakyas essentially say the same in a concise form. The subject matter and the essence of all Upanishads being the same, all the Mahaavaakyas essentially say the same in a concise form: Prajnanam Brahma “Consciousness is Brahman” (Aitareya Upanishad, Rig Veda), Ayam Aatma Brahma “This self (Atman) is Brahman” (Mandukya Upanishad, Atharva Veda), Tat Tvam Asi “Thou Art That” (Chandogya Upanishad, Sama Veda) and Aham Brahmasmi “I Am Brahman” (Brhadaranyaka Upanishad, Yajur Veda).