vacanad deva-devasya
visnor visvatmanah prabhoh
vahanatve vrtas tasya
babhuvendro maha-vrsah
vacanat—by the order or the words; deva-devasya—of the Supreme Lord of all demigods; visnoh—Lord Visnu; visva-atmanah—the Supersoul of the entire creation; prabhoh—the Lord, the controller; vahanatve—because of becoming the carrier; vrtah—engaged; tasya—in the service of Puranjaya; babhuva—he became; indrah—the King of heaven; maha-vrsah—a great bull.
Puranjaya agreed to kill all the demons, on the condition that Indra would be his carrier. Because of pride, Indra could not accept this proposal, but later, by the order of the Supreme Lord, Visnu, Indra did accept it and became a great bull carrier for Puranjaya.

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