यदा वै सुखं लभतेऽथ करोति नासु-खं लब्ध्वा करोति सुखमेव लब्ध्वा क-रोति सुखं त्वेव विजिज्ञासितव्यमितिसुखं भगवो विजिज्ञास इति ॥ १ ॥
In plain words
When a person finds joy, then he acts; he does not act out of sorrow, but only after touching joy does he engage in action. Yet that very joy must be inquired into. 'Venerable sir, it is happiness that I wish to understand.'
Close to the Sanskrit
When indeed one obtains happiness, then one acts; not having obtained unhappiness does one act; having obtained happiness indeed one acts. Happiness, however, must be inquired into. 'Happiness, venerable sir, I wish to know.'