Mbh 3.191.3d

But having obtained her, the king became deeply enamoured of her in consequence of her companionable virtues, and feeling that he had, as it were, obtained the sovereignty of the three worlds, he bowed down to the king of the frogs and reverenced him in due form and then with utterance choked in joy and tears said, ‘I have been favoured indeed!’ And the king of the frogs obtaining the leave of his daughter, returned to the place from which he had come and some time after the king begot three sons upon her and those sons were named Sala and Dala and Vala, and some time after, their father, installing the eldest of them of all on the throne and setting his heart on asceticism, retired into the forest. One day Sala while out a-hunting, beheld a deer and pursued it, on his car, and the prince said to his charioteer, ‘Drive thou fast.’ And the charioteer, thus addressed, replied unto the king, saying, ‘Do not entertain such a purpose. This deer is incapable of being caught by thee. If indeed Vami horses had been yoked to thy car, then couldst thou have taken it.’ Thereupon the king addressed his charioteer, saying, ‘Tell me all about Vami horses, otherwise I will slay thee,’ Thus addressed the charioteer became dreadfully alarmed and he was afraid of the king and also of Vamadeva’s curse and told not the king anything and the king then lifting up his scimitar said to him, ‘Tell me soon, else I will slay thee.’ At last afraid of the king, the charioteer said, ‘The Vami horses are those belonging to Vamadeva; they are fleet as the mind.’ And unto his charioteer who had said so, the king said, ‘Repair thou to the asylum of Vamadeva.’ And reaching the asylum of Vamadeva the king said unto that Rishi, ‘O holy one, a deer struck by me is flying away. It behoveth thee to make it capable of being seized by me by granting me thy pair of Vami horses.’ The Rishi then answered him saying, ‘I give thee my pair of Vami horses.