CHĀNDOGYA UPANISHAD · 3.15.7

अथ यद् अवोचं स्वः प्रपद्य इत्य् ऋग्वेदं प्रपद्ये यजुर्वेदं प्रपद्ये सामवेदं प्रपद्य इत्य् एव तद् अवोचम् ॥

atha yad avocaṃ svaḥ prapadya ity ṛgvedaṃ prapadye yajurvedaṃ prapadye sāmavedaṃ prapadya ity eva tad avocam ॥

'When I said, I turn to Svah, what I said is, I turn to the Rig-veda, Yagur-veda, and Sâma-veda. That is what I said, yea, that is what I said.'

F. Max Müller · The Upanishads, Sacred Books of the East 1 (1879)