Mahabharata 12.22.9

त्यक्त्वा संतापजं शोकं दंशितो भव कर्मणिक्षत्रियस्य विशेषेण हृदयं वज्रसंहतम्

tyaktvā saṃtāpajaṃ śokaṃ daṃśito bhava karmaṇikṣatriyasya viśeṣeṇa hṛdayaṃ vajrasaṃhatam

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