Dying, Dasharatha tells Kausalya a story he has kept to himself for a lifetime, and the epic gives it to him as the explanation of his death.
As a young man he had the skill of shooting at a sound without seeing the target. Hunting by a river at night he heard water being drawn and shot, taking it for an elephant drinking, and found he had hit a boy who had come to fill a pot. The boy told him that his parents, both blind, were waiting in the forest for the water, and asked him to go to them. Dasharatha carried the water and the news. The father, when he understood, told him that he too would die grieving for a son, and added that the curse was not vengeance but the simple statement of what such an act returns.
The framing is deliberate. The Ramayana has already given the exile a full and sufficient cause in the two boons and in Manthara's persuasion, and it then supplies a second cause running underneath the first, so that the calamity is at once a piece of court politics and the maturing of a debt incurred by accident decades before.
His four sons, in the same design, were born from a sacrifice performed to end his childlessness, in which the offering was divided among his three queens. A man who obtained his children by ritual loses them by a curse, and the poem sets the two events at opposite ends of his life without ever stating the symmetry.