MUṆḌAKA UPANISHAD · 1.2.13

तस्मै स विद्वानुपसन्नाय सम्यक्
प्रशान्तचित्ताय शमान्विताय ।
येनाक्षरं पुरुषं वेद सत्यं प्रोवाच
तां तत्त्वतो ब्रह्मविद्याम् ॥ १३॥

tasmai sa vidvānupasannāya samyak
praśāntacittāya śamānvitāya ।
yenākṣaraṃ puruṣaṃ veda satyaṃ provāca
tāṃ tattvato brahmavidyām ॥ 13॥

To him because he has taken entire refuge with him, with a heart tranquillised and a spirit at peace, that man of knowledge declares in its principles the science of the Brahman by which one comes to know the Immutable Spirit, the True and Real.

Sri Aurobindo · CWSA 18, p. 136