Unintentionally creating merit

This story is about a householder called Palchen, who lived during Buddha's own time. He was an old man about a hundred years old, and as an old man he wasn't able to work actively to contribute to the family. So his wife, his children and his household started to torment him, making his life a misery. He felt very sad and thought that the best thing for him now was to become a monk. He went to the Sangha community and asked permission to become a monk.

To be a monk or a nun the applicant must have at least one merit that can become the basis for receiving the vows. The monks checked to see whether he had any merits, and after checking they thought that he had none. So the old man went to consult Shariputra and Maugalyayana, the great disciples of Buddha, known for their wisdom and psychic power. They checked with their clairvoyance to see whether this old monk had any merit accumulated from some distant past life. But they didn't see any merit, and he was refused permission to be a monk.

The Buddha sent Maugalyayana to fetch the old man and bring him to him. The old man was brought to the Buddha and Buddha gave him a word of encouragement, saying, "You do have some merit that you accumulated in an extraordinarily distant past life. It is so far back in the past that although Shariputra and Maugalyayana are Arhats with extrasensory perception, their extrasensory perception is not powerful enough to reach so far back into the past. However as a Buddha I see one merit for you."

The old man asked, "What kind of merit do I have?"

The Buddha said, "You have a merit you unintentionally accumulated in the very distant past, at a time when you had been born as a worm in a cow-pat. This cow-pat was dry on the surface and soft inside, and you were able to live inside it. One day there was heavy rain and flooding in that area. Everything was washed away by the flood and your cow-pat house and you were washed down into the plains. Down there there was a stupa and around it was a shallow channel worn by the feet of the people who circumambulated it. The current of water from the flood ran into this channel and went round and round, and everything in the water also went round. Thus you unintentionally circumambulated the stupa at that time." ~ Venerable Thupten Rinpoche