Why did Hanuman give his three hairs to Bhima?

Once Narad Muni came to the Pandavas and told Yudhishthir that your father Pandu is sad in heaven. When asked the reason, he said that Pandu wanted to perform Rajsuya Yagya during his lifetime, but he could not do it, so you should do so so that his soul can rest in peace.

Then Pandavas organized Rajasuya Yagya, to make the event grand, Yudhishthira decided to invite sage Purusha Mriga, a great devotee of Lord Shiva, to the yagya. Rishi Purush Mriga was like his name since birth. Half of his body was that of a man and his legs were like those of a deer. The responsibility of finding and calling them was entrusted to Bhima. When Bhima set out in search of Purushmriga, Shri Krishna warned Bhima that if he could not match the speed of Purushmriga, he would kill you.

Frightened by this, Bhima set out towards the Himalayas in search of Purushmriga. While passing through the forest he met Hanuman ji. Hanuman ji asked Bhima the reason for his worry. Bhima told the whole story to Hanuman. Hanuman said that it is true that the speed of Purushmriga is very fast and no one can compete with it. There is only one way to slow down its speed. Since he is a great devotee of Lord Shiva, if we build a Shivalinga on his way, he will definitely stop to worship it.

Saying this, Hanuman gave three of his hairs to Bhima and said that whenever you feel that the male deer is going to catch you, then you should drop one hair there. This one hair will be converted into 1000 Shivalingas. The male deer will worship each Shivling according to its nature and you go ahead.

After that Bhima proceeded forward with permission. After going some distance, Bhima found male deer who were praising Lord Mahadev. Bhima saluted him and told him the reason for his coming, on which the sage conditionally agreed to go.

The condition was that Bhima had to reach Hastinapur before him and if he could not do so then the sage Mriga would eat Bhima. Keeping his brother’s wish in mind, Bhima agreed and ran with full force towards Hastinapur. After running for a long time, Bhima turned around to see whether the male deer was following him or not, and was shocked to find that the male deer was about to catch him. Then Bhima remembered Hanuman’s hair and dropped one of them, the fallen hair turned into a thousand Shivalingas.

Being a great devotee of Shiva, Purushumriga started paying obeisance to every Shivalinga and Bhima kept running away. Bhima did this three times and when he was about to enter the gate of Hastinapur, Purushmriga caught Bhima, although Bhima jumped but his feet remained outside the door.

On this Purushmriga wanted to eat Bhima, during this time Krishna and Yudhishthar reached the door. Seeing both of them, Bhima also started arguing, then Purushmriga asked Yudhishthir to do justice. Then Yudhishtra said that Bhima’s feet were left outside the door. Therefore, you are entitled to eat only Bhima’s feet. Purushmriga was pleased with Yudhishthira’s justice and spared Bhima. He participated in Rajsuya Yagya and also blessed everyone.