Bhīṣma knew that Karṇa was Kuntī’s son through Devarṣi Nārada, Kṛṣṇa Dvaipāyana Vyāsa, and Bhagavān Kṛṣṇa (Keśava).
On hearing that Bhishma had been brought down, Radheya, bull among men, swiftly came to him, partly because he was terrified. He saw the great-souled one, lying down on his bed of arrows, like the lord, the god Kartikeya, lying down after his birth. The brave one’s eyes were closed. His voice choked with tears, Vrisha (Karna) worshipped the feet of the immensely radiant one who had fallen down. ‘O best of the Kurus! I am Radheya. I have been in your sight, but you have always regarded me with hate.’ He spoke these words. On hearing these words, the aged Kuru used his strength to slowly open his closed eyes and glanced at him. He spoke these affectionate words. He asked the guards to leave and once they were alone, glanced at him with benevolence.
‘“Gangeya embraced him with one arm, like a father towards a son. ‘Come. Come. You have always been my adversary and have always sought to rival me. If you had not come before me, there is no doubt that it would not have been good for you. You are a Kounteya(son of Kunti). You are not Radheya. I have known this from Narada and from Krishna Dvaipayana and Keshava.
- CHAPTER 977(117) Bhishma Vadha Parva, Mahabharata