Mahabharata 14.94.6

अथ कस्मात्स नकुलो गर्हयामास तं क्रतुम्अश्वमेधं महायज्ञं राज्ञस्तस्य महात्मनः

atha kasmātsa nakulo garhayāmāsa taṃ kratumaśvamedhaṃ mahāyajñaṃ rājñastasya mahātmanaḥ

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