When King Yayati said that he had not yet satisfied his lusty desires with Sukracaryas daughter, Sukracarya saw that it was against the interests of his own daughter for Yayati to continue in old age and invalidity, for certainly his lusty daughter would not be satisfied. Therefore Sukracarya blessed his son-in-law by saying that he could exchange his old age for someone elses youth. He indicated that if Yayatis son would exchange his youth for Yayatis old age, Yayati could continue to enjoy sex with Devayani.