a famous mythology about the existence of Lake Toba, which teaches us to be careful in every oath and speech. every speech can be a prayer can also be a curse, and breaking the oath can be a disaster.that is what happened to the story of Samosir who turned into a fish due to the father who forgot his oath and not careful in utterance so that for his mistake his son Samosir turned into a fish that is now d believe by the community as the inhabitants of Lake Toba.