“Yea, for my father’s promise sake I to the wood my way will take, And dwell a lonely exile there In hermit dress with matted hair. One thing alone I fain would learn, Why is the king this day so stern?

In plain words: Rama agrees to go and live alone in the forest, dressed like a hermit with matted hair, so that his father's promise is kept. He only wants to know why the king seems so harsh today.