Agnibheda–Vaṃśa: Forms of Agni, Their Functions, and Progeny (अग्निभेद-वंशः)
तथा सव्यापसव्यौ च शंस्यस्याग्नेः सुतावुभौ / शंस्यस्तु षोडश नदीश्चकमे हव्यवाहनः
tathā savyāpasavyau ca śaṃsyasyāgneḥ sutāvubhau / śaṃsyastu ṣoḍaśa nadīścakame havyavāhanaḥ
So too, Agni Śaṃsya has two sons, Savya and Apasavya. And Śaṃsya, the Havyavāhana, chose sixteen rivers as his consorts.