Mahabharata 5.88.20
राजर्षीणां पुराणानां धुरं धत्ते दुरुद्वहाम्शीलवृत्तोपसंपन्नो धर्मज्ञः सत्यसंगरः
rājarṣīṇāṃ purāṇānāṃ dhuraṃ dhatte durudvahāmśīlavṛttopasaṃpanno dharmajñaḥ satyasaṃgaraḥ
Our plain-language meaning of this verse is waiting for scholar review.
Open in the book