Devibhagavatapurana 2.6.49

2.6.49

ityākarṇya tadā prāha kuntīṃ kamalalocanām |
sutamutpādayāśu tvaṃ muniṃ gatvā tapo'nvitam ||

Hearing this, Pându spoke to the lotus-eyed Kunti to procreate sons for him soon by a great ascetic Muni:-- “By my order, you will not incur any sin in doing this. I heard that in ancient times the high souled kin Saudâsa got son from Vas'istha.” Kunti, then spoke to the king:-- “O Lord! I know one Siddha mantra; it was given to me before by the Muni Durvâsâ. Whichever Devatâ I will invoke by that Mantra, he will instantly come to my side, controlled by that Mantra.”