Mbh 12.1.4a

"'Yudhishthira said, "Indeed the whole Earth hath been subjugated by me through my reliance on the might of Krishna's arms, through the grace of the Brahmanas, and through the strength of Bhima and Arjuna. This heavy grief, however, is always sitting in my heart, viz., that through covetousness I have caused this dreadful carnage of kinsmen. Having caused the death of the dear son of Subhadra, and of the sons of Draupadi, this victory, O holy one, appears to me in the light of a defeat. What wilt Subhadra of Vrishni's race, that sister-in-law of mine, say unto me? What also will the people residing in Dwaraka say unto the slayer of Madhu when he goes thither from this place? This Draupadi, again, who is ever engaged in doing what is agreeable to us, bereaved of sons and kinsmen, is paining me exceedingly. This is another topic, O holy Narada, about which I will speak to thee. In consequence of Kunti having kept her counsels close in respect of a very important matter, great has been my grief. That hero who had the strength of ten thousand elephants, who in this world was an unrivalled car-warrior, who was possessed of leonine pride and gait, who was endued with great intelligence and compassion, whose liberality was very great, who practised many high vows, who was the refuge of the Dhartarashtras, who was sensitive about his honour, whose prowess was irresistible, who was ready to pay off all injuries and was always wrathful (in battle), who overthrew us in repeated encounters, who was quick in the use of weapons, conversant with every mode of warfare, possessed of great skill, and endued with wonderful valour (that Karna) was a son of Kunti, born secretly of her, and therefore, a uterine brother of ours. Whilst we were offering oblations of water unto the dead, Kunti spoke of him as the son of Surya. Possessed of every virtue, that child had been cast into the water.