Did you know that Hanuman made a few special appearances in the Mahabharata? This is the story of one of Hanuman's special appearances in the Mahabharata when he meets Arjuna. Here's what follows...
Once Arjuna was visiting the south of India, he visited Rameshwaram where the Rama Setu was built. A monkey nearby caught him staring at it for a long time, and asked him what he was thinking. Arjuna wondered why had Sri Rama not built the bridge himself, such a talented archer that he was. The monkey mentioned that a bridge of arrows would not have been able to withstand the weight of all those who would walk upon it, let alone stalwarts like Sugriva or Hanuman! Arjuna challenged him that he could definitely build such a bridge, failing which he would willingly walk in to a pyre to give up his life! He then built the bridge within a few minutes and the monkey got ready to try it out. No longer had the monkey put one foot on it, that the bridge collapsed! Ashamed, Arjuna was about to walk in to the pyre when a young brahmin boy walked in to the scene.
The boy asked them what the commotion was all about. On hearing the story, he mentioned that since this was a wager, there should have been an impartial third party judge who could make the right observation and make an objective decision. And so it was decided that Arjuna would make a bridge yet again and the monkey would try walking on it, with the young boy as the judge.
After the bridge was completed, the monkey walked on it but to Arjuna's and the monkey's surprise, this time it did not give way! The monkey revealed his true form - he was the mighty Hanuman. He started to jump on the bridge with all his might but even then, nothing happened! Jumping and looking around frantically in his shock, he spotted a serene smile on the young boy's face. He immediately realised that boy might not be a normal human child. He turned towards the boy, and requested him to reveal his true identity.
And who was this little boy, you think? None other than Vishnu himself! Both Arjuna and Hanuman apologized for their egoistic behaviour, and the God blessed them. Hanuman even promised Arjuna that he would protect his chariot during the war from all celestial weapons. So much so, that after the war was over, and Arjuna and his charioteer Krishna had alighted from the chariot, it burst in to flames, indicating the amount of protection it had from Hanuman!