Mahāvākya

Mahāvākyas (Sanskrit: "Grand Pronouncement; Great Sayings") — more specifically it refers to four Upanishadic quotations which affirm the reality of atman (the Self): (1) Tat Tvam Asi, "That thou art", (2) Aham Brahmasmi, "I am Brahman", (3) Ayam Atma Brahma, "This Self is Brahman", (4) Prajnanam Brahma, "consciousness is Brahman". The four statements indicate the ultimate unity of the atman (individual) with Brahman (Supreme Being).