Mahabharata 14.92.2
वैशंपायन उवाच · vaiśaṃpāyana uvāca
श्रूयतां राजशार्दूल महदाश्चर्यमुत्तमम्अश्वमेधे महायज्ञे निवृत्ते यदभूद्विभो
śrūyatāṃ rājaśārdūla mahadāścaryamuttamamaśvamedhe mahāyajñe nivṛtte yadabhūdvibho
Our plain-language meaning of this verse is waiting for scholar review.