CHĀNDOGYA UPANISHAD · 6.1.1

श्वेतकेतुर् हारुणेय आस ।
तं ह पितोवाच श्वेतकेतो वस ब्रह्मचर्यम् ।
न वै सोम्यास्मत् कुलीनो ऽननूच्य ब्रह्मबन्धुर् इव भवतीति ॥

śvetaketur hāruṇeya āsa ।
taṃ ha pitovāca śvetaketo vasa brahmacaryam ।
na vai somyāsmat kulīno ’nanūcya brahmabandhur iva bhavatīti ॥

Harih, Om. There lived once Svetaketu Âruneya (the grandson of Aruna). To him his father (Uddâlaka, the son of Aruna) said: 'Svetaketu, go to school; for there is none belonging to our race, darling, who, not having studied (the Veda), is, as it were, a Brâhmana by birth only.'

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