In Mahabharata, how did Bheeshma know that Karna was Kunti's son. Who revealed it to Bheeshma? Bhishma knew that Karna was the son of Kunti through Narada and Vedavyasa. When Karna came to visit Bhishma when he was on the bed of arrows, Bhishma tells him that is Kunti’s son. Hearing of Bhishma's slaughter that bull among men, viz., Radha's son (Karna), partially inspired with fear quickly came there. He beheld that illustrious hero lying on his bed of reeds. Then Vrisha (Karna) endued with great glory, with voice choked in tears, approaching that hero lying with eyes closed, fell at his feet. And he said,--O chief of the Kurus, I am Radha's son, who while before thy eyes, was everywhere looked upon by thee with hate!--Hearing these words, the aged chief of the Kurus, the son of Ganga, whose eyes were covered with film slowly raising his eyelids, and causing the guards to be removed, and seeing the place deserted by all, embraced Karna with one arm, like a si...