The king of this planet, Mahārāja Ambarīṣa, thus performed devotional service to the Lord and in this endeavor practiced severe austerity. Always satisfying the Supreme Personality of Godhead by his constitutional activities, he gradually gave up all material desires.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
स इत्थं भक्तियोगेन तपोयुक्तेन पार्थिवः । स्वधर्मेण हरिं प्रीणन् सङ्गान् सर्वान् शनैर्जहौ
sa itthaṃ bhaktiyogena tapoyuktena pārthivaḥ | svadharmeṇa hariṃ prīṇan saṅgān sarvān śanairjahau
SB 9.4.26