Mahabharata 13.109.42
षष्ठे काले तु कौन्तेय नरः संवत्सरं क्षपेत्अश्वमेधस्य यज्ञस्य फलं प्राप्नोति मानवः
ṣaṣṭhe kāle tu kaunteya naraḥ saṃvatsaraṃ kṣapetaśvamedhasya yajñasya phalaṃ prāpnoti mānavaḥ
Our plain-language meaning of this verse is waiting for scholar review.
Open in the book