Dronacharya was the teacher of both the Kauravas and Pandavas. The Pandavas and the Kauravas learnt all forms of knowledge from their Guru. Amongst all the students, Arjuna indeed was the favourite student of Drona. The Pandavas and Kauravas specialized themselves in the art of warfare. Arjuna in archery, Bhima and Duryodhana in fighting with mace and so on.
Dronacharya had a son by name Ashwathama. When Ashwathama was born, he made sounds similar to that of a horse (ashwa). Hence he was named as Ashwathama. Drona always had a soft corner for his son. Dronacharya himself trained his son in archery and very soon, Ashwathama grew up to become one of the best archer and warrior.
Ashwathama knew that his father Drona had a soft corner for Arjuna, and therefore he disliked the Panadavas. He also knew that Krishna always favoured the Pandavas, because they were always on the side of righteousness. If at all there was a war between the Pandavas and Kauravas in future, he was sure that Krishna would definitely support the Pandavas.
Krishna had a very powerful weapon – the Sudarshana Chakra which is attributed only to Lord Narayana. In order to gain lordship over the Divine Disc, Ashwathama thought of going to Krishna and getting the Sudarshana Chakra for himself by bargaining with the most powerful weapon he had – the Brahma-astra. He immediately left for Dwaraka and met Krishna. He put forth his proposal in front of Krishna. He would give Krishna the most powerful weapon which he had which could kill anyone, in exchange for the Sudarshana Chakra. Krishna smiled and immediately invoked His divine weapon, the Sudarshana Chakra. It immediately appeared in front of Him in all its brilliant lustre. Krishna then asked Ashwathama to lift the Chakra and take with him if he could.
Ashwathama who was physically very strong was extremely happy. He was very confident that he could lift it up as easily as lifting up a feather! He came forward and tried to lift the Sudarshan, but he could not. Again and again he tried with all his might and strength, but the Chakra did not budge even a bit. Krishna smiled and then told Ashwathama who was not even capable of lifting the Sudarshana to be happy with whatever weapons he had, and use them in warfare. Ashwathama was embarrassed and ashamed and realized that true ability and strength has to be acquired by one’s own effort and cannot be exchanged in a barter system.
[PS: I request all to please forward and share these value based stories rich in our culture and tradition to elders, youth and children]