The Four Mahavakyas (Great Sayings) from the Vedas:
From Yajurveda – "Aham Brahmasmi" (I am Brahman)
From Samaveda – "Tat Tvam Asi" (You are That / You are Brahman)
From Rigveda – "Prajnanam Brahma" (Brahman is Pure Consciousness)
From Atharvaveda – "Ayam Atma Brahma" (This Soul is Brahman)