The Race of Varuna : Birth of Asvin Gods1 - Verse 23-24

Assuming the form of a mare, the noble lady went to the land of Kurus. The blessed lady bore two sons to the Sun who had assumed the form of a horse. She gave birth to them through nostrils. They were the twin gods, the Asvins, Nasatya and Dasra. Both of them were the sons of Martan<Ja (the Sun-god). The Sages enqu ired :