In Hindu philosophy, the Sanskrit sentence - Aham Brahmāsmiti (Devanagari: अहं ब्रह्मास्मिति)- means I am of Brahman"(Aham Brahmasmi) or "I am the Infinite Reality". It is one of the four Mahavakyas used to explain the unity of macrocosm and microcosm.
Literally, Aham (अहं) means "I"--that which cannot be deserted or abandoned on account of being constant, unavoidable, ever present; Brahman (ब्रह्म) means ever-full or whole (ब्रह्म is the first case ending singular of Brahman); and Asmi (अस्मि) means "am," the first-person singular present tense of the verb "अस्," "to be." This mahāvākya खधखbeloगngs to the Brihadaranyaka Upanishad of the Shukla Yajurveda.धनंनंनंधधखBrahman is the Infinite Reality, the all encompassing existगकence in itself; only when the ego dies can this be realized. In this sentence the "I" is not the limited transmigrating ego, the doer and the enjoyer within, and also not the body and the mind. Man (who is a conscious entity) alone has the capacity to improve his present state, to guide his future, to enquire and know the truth, and to free himself from the cycle of birth and death (vidyā adhikāra) through thoughtful actions (karma adhikāra). Vidyāranya in his Panchadasi (V.4) explains:
This realization is gained through true enquiry.
Vaishnavas, when they talk about Brahman, usually refer to impersonal Brahman, brahmajyoti (rays of Brahman). Brahman according to them means God - Narayana, Rama or Krishna. Thus, the meaning of "aham brahma asmi" according to their philosophy is that "I am a drop of Ocean of Consciousness", or "I am soul, part of cosmic spirit, Parabrahman". Here, the term Parabrahman is introduced to avoid confusion. If Brahman can mean soul (though, Parabrahman is also the soul, but Supreme one - Paramatma), then Parabrahman should refer to God, Lord Vishnu. Real problem with "aham brahma asmi" is that Brahman also means mahat-tattva - material substance. Lord Krishna says in Bhagavad-Gita: “The total material substance, called Brahman, is the source of birth, and it is that Brahman that I impregnate, making possible the births of all living beings, O son of Bharata.” So, Parabrahman, Ishvara, is the source of Brahman - two energies: conscious Brahman (souls, jiva-atamas or tatastha-shakti) and unconscious Brahman (matter).