A battle broke out between Ravana's demon army and Rama's animal army. Lakshman was so badly wounded in the battle it seemed that he would die before sun-rise. (In some versions of the story, many monkeys and bears are wounded too.) The monkeys and bears decided that Hanuman must leap to the Himalayas and bring back the healing herb from the Medicine Mountain to save Lakshman's life. So Hanuman leapt over the ocean, and across the whole of India to the Himalayas.
Arriving in the Himalayas, it took a long time to find the fabled Medicine Mountain. Hanuman found it at last -covered with herbs, but he didn't know which was the magic healing herb. So he wrapped his arms around the whole mountain, pulled it out of the ground and lifted it onto the palms of his hand. He then flew with the mountain back to Lanka. (Hanuman carrying the mountain is reproduced again and again in all forms of art.) On the way the sun began to rise. So Hanuman decided to capture the sun under his arm so that he could arrive back before sunrise in time to save Lakshman. The healing herb was picked and given to Lakshman. Lakshman was healed and filled with energy.