Mahabharata 13.48.41

पित्र्यं वा भजते शीलं मातृजं वा तथोभयम्न कथंचन संकीर्णः प्रकृतिं स्वां नियच्छति

pitryaṃ vā bhajate śīlaṃ mātṛjaṃ vā tathobhayamna kathaṃcana saṃkīrṇaḥ prakṛtiṃ svāṃ niyacchati

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