yadṛcchayopapannena
yadṛcchayopapannena santuṣṭo vartate sukham |
nāsantuṣṭas tribhir lokair ajitātmopasāditaiḥ ||
(Śrīmad Bhāgavatam: 8.19.24)
“[Vāmanadeva to Bali Mahārāja:] One who is satisfied with that which it attained of its own accord is happy. One who has not controlled oneself [i.e., one’s senses] is not satisfied even upon having attained the three worlds.”