Rama Confronts the Ocean and Obtains a Bridge
Rama asks Sugriva how to cross the ocean. The monkeys propose leaping or building boats, but Rama rejects both — the army is too vast, and trade should not suffer. He decides to force the ocean god himself to yield a path, threatening to dry up the sea with celestial weapons. The ocean god appears in a dream and offers a solution: Nala, son of Vishvakarma, will build a bridge that the ocean will bear.
In the midst of the chiefs among the monkeys, Dasharatha's illustrious son told Sugriva words that were appropriate for the occasion. "What do you think is the way to cross over the ocean? This army is large and the ocean is difficult to cross."
Some monkeys, who thought of themselves as learned, thought that the monkeys were capable of jumping over the ocean. Others thought of boats and other means of crossing.
But having comforted all of them, Rama replied: "No. O brave ones! All the monkeys are not capable of leaping over this expanse of one hundred yojanas. Therefore, this cannot be a firm view. There are not enough boats to bear this army. Besides, the interests of trade should not suffer because of us. Our army is vast and the enemy will look for weak spots. The idea of leaping, or using boats, does not appeal to me. No. I will attack this treasure of water through some means and the one who lives below will then show me a way. If he does not show me a path, I will burn him up with great and unassailable weapons that flame with the fire and the wind."
Having said this, Raghava, together with Soumitri, touched the water, and basing themselves on an expanse of kusha grass, repulsed the ocean.
Then the god of the ocean, the illustrious lord of male and female rivers, showed himself in a dream to Raghava, surrounded by masses of aquatic creatures. Surrounded by hundreds of stores of gems, he addressed him in sweet words. "O son of Kousalya! O bull among men! Tell me what I can do to help you."
Rama told him: "I am of the Ikshvaku lineage and can therefore be regarded as your relative. O lord of the male and female rivers! I desire that you show me a path for my army, so that I can go and kill Dashagriva, the wretch of the Poulastya lineage. If you do not give me the path that I am asking for, I will dry you up with arrows that have been invoked with mantras to make them celestial weapons."
On hearing Rama's words, Varuna's abode was extremely aggrieved and stood there, hands joined in salutation. It spoke these words: "I do not wish to obstruct you, or create any obstacles. O Rama! Listen to my words. Having heard, decide on your course of action. If I grant a passage for your marching army at your request, others will use the strength of their bows to also command me. There is a monkey named Nala who is venerated by the artisans. He is the powerful son of the god Vishvakarma Tvashtra. I will bear whatever he throws into me — wood, straw or stone, and that will become a bridge."
Having said this, he disappeared.
Rama told Nala: "Build a bridge across the ocean. It is my view that you are capable of doing this."
Through this means, Kakutstha had a bridge constructed. It was ten yojanas wide and a hundred yojanas long. Even today, that is famous on earth as Nala's bridge. It was created on Rama's instructions and is established like a mountain. Aranyaka Parva, Chapter 564