ChU 7.22.1
यदा वै सुखं लभते ऽथ करोति । नासुखं लब्ध्वा करोति । सुखम् एव लब्ध्वा करोति । सुखं त्व् एव विजिज्ञासितव्यम् इति । सुखं भगवो विजिज्ञास इति
yadā vai sukhaṃ labhate 'tha karoti | nāsukhaṃ labdhvā karoti | sukham eva labdhvā karoti | sukhaṃ tv eva vijijñāsitavyam iti | sukhaṃ bhagavo vijijñāsa iti
Devanagari rendered by HREEM from the edition's roman (IAST) text; the IAST is the edition's own.
'When one obtains bliss (in oneself), then one performs duties. One who does not obtain bliss, does not perform duties. Only he who obtains bliss, performs duties. This bliss, however, we must desire to understand.' 'Sir, I desire to understand it.'
Translated by F. Max Müller