Canonical Reference: Paharada Sutta Verified Source

“Just as the great rivers, on reaching the great ocean, lose their former names and identities and are reckoned simply as the great ocean; even so people of all castes and backgrounds, having gone forth into this Dhamma, lose their former names and classes and become equals.”

Canonical Pali Original: Seyyathāpi, bhikkhave, yā kāci mahānadiyo... mahāsamuddaṃ patvā jahanti purimāni nāmagottāni, mahāsamuddotveva saṅkhaṃ gacchanti; evamevaṃ kho, bhikkhave, cattārome vaṇṇā...

— Gautam Buddha
The Awakened One, Founder of Dhamma
Historical Setting & Context:

Classic canonical proclamation of absolute social and spiritual equality in the Buddhist Sangha regardless of caste origins.