Srimad-Bhagavatam: Canto 7 - Chapter 1 - Verse 44
Sanskrit:
ततस्तौ राक्षसौ जातौ केशिन्यां विश्रव:सुतौ ।रावण: कुम्भकर्णश्च सर्वलोकोपतापनौ ॥ ४४ ॥
ITRANS:
tatas tau rākṣasau jātaukeśinyāṁ viśravaḥ-sutaurāvaṇaḥ kumbhakarṇaś casarva-lokopatāpanau
Translation:
Thereafter the same Jaya and Vijaya, the two doorkeepers of Lord Viṣṇu, took birth as Rāvaṇa and Kumbhakarṇa, begotten by Viśravā in the womb of Keśinī. They were extremely troublesome to all the people of the universe.