Panchatantra story-The geese and the tortoise
Once upon a time there lived a pair of geese and a tortoise and all three were great friends. One day they faced a huge drought and the lake in which they lived was drying up. They decided to leave the lake and look for a new lake. But the tortoise could not fly. So the geese thought of a plan, where by the tortoise would have to hold a piece of stick by its mouth which would be carried by the two geese. The only condition was that the tortoise should not speak or it will fall from the stick to death. The tortoise agreed to be silent.
But on seeing this strange arrangement, people on the way started laughing at the tortoise. Unable to control his anxiety, he spoke out "What are they laughing about?", and so he fell to his death. If he had kept quiet he could have saved his own life.
Story moral: Destiny cannot be changed