Skandapurana 7.20.118

7.20.118

devyā kauśikī kimarthaṃ vindhyācale saṃpreṣiteti vyāsasya jijñāsā . prasaṃgād vindhyakṛtādityamārgāvarodhanāgastyakṛta tadavamānakathākhyānam. sundanisundopākhyāna prasaṃgena gokarṇakṣetrotpattyākhyānam . gokarṇe sundanisundayo- stapaścaryā, brahmaṇaḥ sakāśād varaprāptiḥ .

Vyāsa's inquiry as to why Kauśikī was sent to Mount Vindhya; in that connection, the story of the obstruction of the sun's path by the Vindhya and its subjugation by Agastya; the account of the origin of the sacred field of Gokarṇa in the context of the episode of Sunda and Upasunda; the practice of austerity by Sunda and Upasunda at Gokarṇa, and the attainment of a boon from Brahmā.