Suddhikasutta

Suttapiṭaka · Saṁyuttanikāya · Sagāthāvaggasaṁyutta · Vol. 15 · Section 650

[650] "Though muttering much prattle, one is not a brahmin by birth (jāti) if he is rotten and defiled within, dependent upon deception. Whether khattiya, brahmin, vessa, sudda, caṇḍāla, or pukkusa, one with energy (vīriya) aroused, resolute, always firm in exertion, attains the supreme purity — know it thus, brahmin!"

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.