Karna was famous for his charity. He was popularly known as ' Daanvir Karna '.
But there is only one incident in Mahabharata depicting his charity.
Karna, knowing full well that he was committing a suicidal act,
gave his natural ear-rings and armor to Indra.
Folk were not satisfied with this event. They added some more incidents
which give a clear cut picture of the great charity of Karna:
Once Krishna wanted to show the charity of Karna to Dharma
Raja. He created a big mountain of gold and asked Dharma Raja to
distribute it quickly among the poor. Dharma Raja began his charity
but he could not complete it even after taking months together. Then
Krishna called for Karna and asked him to give the gold in charity.
Immediately Karna, showing the hill of gold to Krishna, said: " Sri
Krishnarpanamastu " (=I offer the whole thing to Sri Krishna).
Dharma Raja was astonished to note this.