Daanveer

Once, Arjuna asked Lord Krishna that why he called Yudhishtira as Dharamaraj, and Karna as Daanveer!

 Krishna wanted to not only answer but also demonstrate it to Arjuna. He disguised himself and Arjuna as Brahmins and both of them visited the kings. 

On visiting Yudhishitra, they asked for sandalwood to cook food. As it was raining heavily at the time, and Yudhishitra could not find dry sandalwood suitable to be used as a fuel, he gently apologized to both of them. So they returned empty-handed!

A little later, they went to Karna and asked for the same thing. Karna searched everywhere for dry sandalwood but failed as it was raining everywhere. But he did not let the Brahmins go home empty-handed. He picked up his bow and arrow and destroyed the doors made of sandalwood! This, he gave to Krishna and Arjuna.