Mahabharata 3.129.2

अम्बरीषश्च नाभाग इष्टवान्यमुनामनुयज्ञैश्च तपसा चैव परां सिद्धिमवाप सः

ambarīṣaśca nābhāga iṣṭavānyamunāmanuyajñaiśca tapasā caiva parāṃ siddhimavāpa saḥ

Our plain-language meaning of this verse is waiting for scholar review.