Mahabharata 4.2.21

अर्जुन उवाच · arjuna uvāca

प्रतिज्ञां षण्ढकोऽस्मीति करिष्यामि महीपतेज्याघातौ हि महान्तौ मे संवर्तुं नृप दुष्करौ

pratijñāṃ ṣaṇḍhako'smīti kariṣyāmi mahīpatejyāghātau hi mahāntau me saṃvartuṃ nṛpa duṣkarau

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