Once a peddler was going home with his ass after buying salt. His home was across the stream. When they reached the stream, the ass accidentally fell into the water. When he got up, his load had been reduced since the salt had dissolved in the water. This delighted the ass. Next time the peddler again loaded him with salt and this time the ass fell down on purpose. He got up again feeling his load lightened and brayed in triumph.
The peddler understood the ass’s trick and decided to teach him a lesson. This time he loaded the ass with sponges instead of salt. So when the ass purposely fell down into the stream, he felt that his load had doubled as the sponges had become laden with water. Thus the ass’s trick backfired on him.