Mahabharata 12.308.160
योऽप्यत्र परमो धर्मः पवित्रं राजराज्ययोःपृथिवी दक्षिणा यस्य सोऽश्वमेधो न विद्यते
yo'pyatra paramo dharmaḥ pavitraṃ rājarājyayoḥpṛthivī dakṣiṇā yasya so'śvamedho na vidyate
Our plain-language meaning of this verse is waiting for scholar review.
Open in the book