Chandogya Upanishad
Prapathaka VII, Khanda 2
'Speech is better than a name. Speech makes us understand the Rig-veda, Yagur-veda, Sâma-veda, and as the fourth the Âtharvana, as the fifth the Itihâsa-purâna, the Veda of the Vedas, the Pitrya, the Râsi, the Daiva, the Nidhi, the Vâkovâkya, the Ekâyana, the Deva-vidyâ, the Brahma-vidyâ, the Kshatra-vidyâ, the Nakshatra-vidyâ, the Sarpa and Devagana-vidyâ; heaven, earth, air, ether, water, fire, gods, men, cattle, birds, herbs, trees, all beasts down to worms, midges, and ants; what is right and what is wrong; what is true and what is false; what is good and what is bad; what is pleasing and what is not pleasing. For if there were no speech, neither right nor wrong would be known , neither the true nor the false, neither the good nor the bad, neither the pleasant nor the unpleasant. Speech makes us understand all this. Meditate on speech.