Mahabharata 7.57.10
मया प्रतिज्ञा महती जयद्रथवधे कृताश्वोऽस्मि हन्ता दुरात्मानं पुत्रघ्नमिति केशव
mayā pratijñā mahatī jayadrathavadhe kṛtāśvo'smi hantā durātmānaṃ putraghnamiti keśava
Our plain-language meaning of this verse is waiting for scholar review.
Open in the book