 With no heir to the throne , Satyavati asked Bhishma to marry the widows of Vichitravirya ( following the practice of niyoga in its narrower sense , as a levirate marriage ) and rule as king . Bhishma refused , reminding Satyavati of the promise he made to her father and his vow of bachelorhood . He suggests that a Brahmin could be hired to father children on the widows , thus preserving the dynasty . Revealing to Bhishma the tale of her encounter with Parashara , Satyavati well knew that this was the time to call her son Vyasa to aid her . Satyavati coaxed Vyasa to have niyoga with his brother 's widows , saying : " from affection for thy brother Vichitravirya , for the perpetuation of our dynasty , for the sake of this Bhishma 's request and my command , for kindness to all creatures , for the protection of the people and from the liberality of thy heart , O sinless one , it behooveth thee to do what I say . " After convincing Vyasa , Satyavati managed ( with great difficulty ) to obtain the consent of her " virtuous " daughters @-@ in @-@ law . In the Mahabharata , Vyasa agreed immediately to the niyoga . In the Devi Bhagavata Purana version , Vyasa initially refused Satyavati 's proposal . He argued that Vichitravirya 's wives were like his daughters ; having niyoga with them was a heinous sin , through which no good could come . As a master of " realpolitik " , the hungry @-@ for @-@ grandsons Satyavati asserted that to preserve the dynasty , wrong directives by elders should be followed if they are going to reduce the sorrow of a mother . Vyasa finally agreed to that " disgusting task " , but suggested that offspring of perversity cannot be a source of joy . 
