Each of them requested Sukanya to be his bride, but she successfully identified Chyavana and selected him, in some accounts, after praying to Adi Parashakti. Sukanya succeeded in identifying Chyavana by observing the eyes of all the three of them; Devas don't blink and thus she picked the person who blinked. In gratitude for his restored youth and eyesight, Chyavana assured the Ashvins that he would ensure that the deities would get their share of the sacrificial offerings.
Each suitor asked Sukanya to be his bride, but she identified Chyavana instead. In some stories, after praying to Adi Parashakti, she noticed the person who blinked; Devas don't blink, so she chose that individual. To express gratitude for his restored youth and eyesight, Chyvana promised the Ashvins he would ensure the deities received their share of the sacrificial offerings.