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 of them asked Sukanya to be their bride, but she successfully recognized Chyavana and chose him. In some accounts, after praying to Adi Parashakti, she identified the person who blinked; Devas don't blink, so she picked that individual. To show gratitude for his restored youth and eyesight, Chyavana promised the Ashvins that he would ensure the deities received their share of the sacrificial offerings.