Amid their ceaseless roar the sound Of Ocean’s fearful voice was drowned, As o’er the bridge by Nala planned They hastened on to Lanká’s strand, Where, by the pleasant brooks, mid trees Loaded with fruit, they took their ease.

In plain words: The army is so loud that it drowns out the roar of the ocean as they rush over the bridge that Nala designed. They reach the shore of Lanka and rest by streams under trees full of fruit.