Śrīmad-Bhāgavatam · Text 5.24.18
Who is speaking and story frame
ततोऽधस्तात्सुतले उदारश्रवा: पुण्यश्लोको विरोचनात्मजो बलिर्भगवता महेन्द्रस्य प्रियं
चिकीर्षमाणेनादितेर्लब्धकायो भूत्वा वटुवामनरूपेण पराक्षिप्तलोकत्रयो भगवदनुकम्पयैव पुन: प्रवेशित
इन्द्रादिष्वविद्यमानया सुसमृद्धया श्रियाभिजुष्ट: स्वधर्मेणाराधयंस्तमेव भगवन्तमाराधनीयमपगतसाध्वस
आस्तेऽधुनापि ॥ १८ ॥
tato ’dhastāt sutale udāra-śravāḥ puṇya-śloko virocanātmajo balir bhagavatā mahendrasya priyaṁ cikīrṣamāṇenāditer labdha-kāyo bhūtvā vaṭu-vāmana-rūpeṇa parākṣipta-loka-trayo bhagavad-anukampayaiva punaḥ praveśita indrādiṣv avidyamānayā susamṛddhayā śriyābhijuṣṭaḥ sva-dharmeṇārādhayaṁs tam eva bhagavantam ārādhanīyam apagata-sādhvasa āste ’dhunāpi.
Below the planet Vitala is another planet, known as Sutala, where the great son of Mahārāja Virocana, Bali Mahārāja, who is celebrated as the most pious king, resides even now. For the welfare of Indra, the King of heaven, Lord Viṣṇu appeared in the form of a dwarf brahmacārī as the son of Aditi and tricked Bali Mahārāja by begging for only three paces of land but taking all the three worlds. Being very pleased with Bali Mahārāja for giving all his possessions, the Lord returned his kingdom and made him richer than the opulent King Indra. Even now, Bali Mahārāja engages in devotional service by worshiping the Supreme Personality of Godhead in the planet of Sutala.
Read Śrīla Prabhupāda's purport on Vedabase.io