RV 1.164.45
चत्वारि वाक् परिमिता पदानि तानि विदुर् ब्राह्मणा ये मनीषिणः । गुहा त्रीणि निहिता नेङ्गयन्ति तुरीयं वाचो मनुष्या वदन्ति ॥
catvāri vāk parimitā padāni tāni vidur brāhmaṇā ye manīṣiṇaḥ | guhā trīṇi nihitā neṅgayanti turīyaṃ vāco manuṣyā vadanti ||
Devanagari rendered by HREEM from the edition's roman (IAST) text; the IAST is the edition's own.
Speech hath been measured out in four divisions, the Brahmans who have understanding know them. Three kept in close concealment cause no motion; of speech, men speak only the fourth division.
Translated by Ralph T. H. Griffith (1896)