Mahabharata 8.18.71

अन्योन्यस्य वधे यत्नं कुर्वाणौ तौ महारथौरथाभ्यां चेरतुस्तत्र मण्डलानि सहस्रशः

anyonyasya vadhe yatnaṃ kurvāṇau tau mahārathaurathābhyāṃ ceratustatra maṇḍalāni sahasraśaḥ

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