All the vanaras helped in the search for Sita. One of the groups which went south learnt from Sampathi, the brother of Jatayu, that Sita was a prisoner of the rakshasas in the island of Lanka.
It was decided that one of the vanaras should leap across the sea to Lanka and make a thorough search for Sita. Jambavan, the oldest of the vanaras, knew that the only vanara suited for this task was Hanuman. So modest was Hanuman that he knew of his own powers only through Jambavan.
Hanuman had with him a signet ring, which Rama had given him. Sita would know from the ring that the bearer was the true messenger of Rama. So, gathering all his strength Hanuman made ready to leap across to Lanka from the top of a high peak.
He reverently prayed to Surya, Indra, Vayu, Brahma and all the bhutas. He joined his hands in obeisance to his father Vayu and assumed an immense aspect.
He gathered up all his vital energies and looked steadfastly at the route he proposed to take. Desirous of taking a flying leap over the sea he pressed the lofty mountain down with his feet.