सर्वँ ह्येतद्ब्रह्मायमात्मा ब्रह्म सोऽयमात्मा चतुष्पात् ॥
sarvam hyetadbrahmāyamātmā brahma so'yamātmā catushpāt ||2||

All this is verily Brahman; this Atman is Brahman; this Atman is quadruped.

This is the Anubhava Vakya, from the Mandukya Upanishad of the Atharva Veda.

anubhava is “perception, fruition, understanding, impression on the mind not derived from memory, experience, or knowledge derived from personal observation or experiment”. And the Anubhava Vakya indicates the direct realization of Brahman.

anubhAva is “a sign or indication of a feeling by a look or gesture, dignity, authority, result, firm opinion, ascertainment, good resolution, or belief”. And the Anubhava Vakya is the ultimate wisdom of the Vedanta.