ChU 7.18.1
यदा वै मनुते ऽथ विजानाति । नामत्वा विजानाति । मत्वैव विजानाति । मतिस् त्व् एव विजिज्ञासितव्येति । मतिं भगवो विजिज्ञास इति
yadā vai manute 'tha vijānāti | nāmatvā vijānāti | matvaiva vijānāti | matis tv eva vijijñāsitavyeti | matiṃ bhagavo vijijñāsa iti
Devanagari rendered by HREEM from the edition's roman (IAST) text; the IAST is the edition's own.
'When one perceives, then one understands. One who does not perceive, does not understand. Only he who perceives, understands. This perception, however, we must desire to understand.' 'Sir, I desire to understand it.'
Translated by F. Max Müller