Shri Hanuman is one the Ekadasa Rudras of Bhagwan Shiv and incarnated to serve Shri Ram as his eternal devotee. The mightiest, intellectual and powerful of all, he is always ready to serve the cause of Shri Ram. However, in one of such occasions, Hanuman faces a situation where he is unable to do a task as ordered by Shri Ram and it has an interesting story.
After killing Ravan, Shri Ram and Mata Sita decide to worship Bhagwan Shiv before returning to Ayodhya. They come to shores of the Ocean after crossing Lanka and make preparations to offer prayers of Bhagwan Shiv. Shri Ram asks Hanuman to go to Kailash Mountain and fetch a Shiv Ling from the divine place as a blessing of Bhagwan Shiv. Hanuman rushes to Mount Kailash to fulfil his master’s task.
When Hanuman reaches Mount Kailash, a young boy stops him at the entrance. He asks Hanuman the purpose for which he has come. Hanuman explains the story of battle of Lanka and how Shri Ram wanted to worship Bhagwan Shiv. The young boy jokingly retorts back that he doesn’t believe that a mere monkey like him had slayed such great warriors of Lanka. Although Hanuman says that it is true and asks him to give way to pass the gate, the young boy does not budge. Instead he says, that he would believe it only if he could see any of the cosmic form of Hanuman.
Hanuman immediately transforms himself into Panchmukh Hanuman standing taller than Kailash Mountain and shows the young boy his power and might. Then the young boy comes to his original form who is none other than Bhagwan Ganesh. Then, Bhagwan Ganesh says that he wanted to see the Panchmukh Hanuman form by which he killed the great demon Mairavan and hence played this small drama. Then he gives Hanuman one of the powerful Shiv Ling and blesses him.
Back at the shores of the Ocean, as time was running out, Shri Ram asks Mata Sita to prepare a Ling out of sand and starts the worship. Meanwhile Hanuman reaches the place and sees that there is another Ling already placed instead of the Ling he bought from Kailash and asks Shri Ram to replace it. Shri Ram smiles and says that he cannot do that, but Hanuman becomes adamant. Shri Ram then says to remove the Ling by himself.
Hanuman tries to pull the sand Ling away with his tail, but it doesn’t budge. In spite of putting all his strength Hanuman fails to move it. Then Shri Ram says that Bhagwan Shiv is not different from Shri Ram and trying to remove the Ling made out of devotion denoted pride in Hanuman for his strength. Hence, he wanted to let know Hanuman the significance of the Bhagwan Shiv and hence the Ling did not move. Hanuman understands his mistake and begs for forgiveness of Shri Ram and accepts his ignorance to understand the power of Shri Ram and Bhagwan Shiv.
Shri Ram then places the Ling Hanuman bought from Kailash beside the Sand Ling and finishes the worship of Bhagwan Shiv. This place where Shri Ram has consecrated Bhagwan Shiv came to be famous as Rameswaram, which means the Eeswar (God) of Shri Ram. Even today, the Sand Ling is the main idol of worship and it receives the primary worship in the temple in the honour of Shri Ram and Mata Sita.