Srimad-Bhagavatam: Canto 4 - Chapter 1 - Verse 4
प्रकृत्या विषमा देवी कृता तेन समा कथम् । तस्य मेध्यं हयं देव: कस्य हेतोरपाहरत् ॥ ४ ॥
prakṛtyā viṣamā devīkṛtā tena samā kathamtasya medhyaṁ hayaṁ devaḥkasya hetor apāharat
The surface of the earth is by nature low in some places and high in others. How did King Pṛthu level the surface of the earth, and why did the King of heaven, Indra, steal the horse meant for the sacrifice?