RV 2.12.3
यो हत्वाहिम् अरिणात् सप्त सिन्धून् यो गा उदाजद् अपधा वलस्य । यो अश्मनोर् अन्तर् अग्निं जजान संवृक् समत्सु स जनास इन्द्रः ॥
yo hatvāhim ariṇāt sapta sindhūn yo gā udājad apadhā valasya | yo aśmanor antar agniṃ jajāna saṃvṛk samatsu sa janāsa indraḥ ||
Devanagari rendered by HREEM from the edition's roman (IAST) text; the IAST is the edition's own.
Who slew the Dragon, freed the Seven Rivers, and drove the kine forth from the cave of Vala, Begat the fire between two stones, the spoiler in warriors' battle, He, O men, is Indra.
Translated by Ralph T. H. Griffith (1896)