Mahabharata 13.109.20
पितृभक्तो माघमासमेकभक्तेन यः क्षपेत्श्रीमत्कुले ज्ञातिमध्ये स महत्त्वं प्रपद्यते
pitṛbhakto māghamāsamekabhaktena yaḥ kṣapetśrīmatkule jñātimadhye sa mahattvaṃ prapadyate
Our plain-language meaning of this verse is waiting for scholar review.
Open in the book