Karṇa's Burden p86

p86

devadūtaḥ: bhoḥ karṇa ! kavacakuṇḍalagrahaṇājjanitapaścāttāpena puraṃdareṇānugṛhīto'si | pāṇḍaveṣvekapuruṣavadhārthamamoghamastraṃ vimalā nāma śaktiriyaṃ pratigṛhyatām |

Divine messenger: O Karṇa! Puraṃdara, filled with remorse for taking your armour and earrings, has granted you a favor. Accept this infallible divine weapon, a spear named Vimalā, to slay one individual among the Pāṇḍavas.