One day, while the Buddha was staying in Jetavana, some bhikkhus asked him if there was any benefit in sacrificing goats, sheep, and other animals as offerings for departed relatives.
“No, bhikkhus,” replied the Buddha. “No good ever comes from taking life, not even when it is for the purpose of providing a Feast for the Dead.” Then he told this story of the past.
Long, long ago, when Brahmadatta was reigning in Baranasi, a brahmin decided to offer a Feast for the Dead and bought a goat to sacrifice. “My boys,” he said to his students, “take this goat down to the river, bathe it, brush it, hang a garland around its neck, give it some grain to eat, and bring it back.”
“Yes, sir,” they replied and led the goat to the river.
While they were grooming it, the goat started to laugh with a sound like a pot smashing. Then, just as strangely, it started to weep loudly.
The young students were amazed at this behavior. “Why did you suddenly laugh,” they asked the goat, “and why do you now cry so loudly?”
“Repeat your question when we get back to your teacher,” the goat answered.
The students hurriedly took the goat back to their master and told him what had happened at the river. Hearing the story, the master himself asked the goat why it had laughed and why it had wept.
“In times past, brahmin,” the goat began, “I was a brahmin who taught the Vedas like you. I, too, sacrificed a goat as an offering for a Feast for the Dead. Because of killing that single goat, I have had my head cut off 499 times. I laughed aloud when I realized that this is my last birth as an animal to be sacrificed. Today I will be freed from my misery. On the other hand, I cried when I realized that, because of killing me, you, too, may be doomed to lose your head five hundred times. It was out of pity for you that I cried.”
“Well, goat,” said the brahmin, “in that case, I am not going to kill you.”
“Brahmin!” exclaimed the goat. “Whether or not you kill me, I cannot escape death today.”
“Don’t worry,” the brahmin assured the goat. “I will guard you.”
“You don’t understand,” the goat told him. “Your protection is weak. The force of my evil deed is very strong.”
The brahmin untied the goat and said to his students, “Don’t allow anyone to harm this goat.” They obediently followed the animal to protect it.
After the goat was freed, it began to graze. It stretched out its neck to reach the leaves on a bush growing near the top of a large rock. At that very instant a lightning bolt hit the rock, breaking off a sharp piece of stone which flew through the air and neatly cut off the goat’s head. A crowd of people gathered around the dead goat and began to talk excitedly about the amazing accident.
A tree deva  had observed everything from the goat’s purchase to its dramatic death, and drawing a lesson from the incident, admonished the crowd: “If people only knew that the penalty would be rebirth into sorrow, they would cease from taking life. A horrible doom awaits one who slays.” With this explanation of the law of kamma the deva instilled in his listeners the fear of hell. The people were so frightened that they completely gave up the practice of animal sacrifices. The deva further instructed the people in the Precepts and urged them to do good.
Eventually, that deva passed away to fare according to his deserts. For several generations after that, people remained faithful to the Precepts and spent their lives in charity and meritorious works, so that many were reborn in the heavens.
The Buddha ended his lesson and identified the Birth by saying, “In those days I was that deva.”
1. Devas are celestial beings, ranging from the highest gods to simple tree spirits.
~ From Jataka Tales of the Buddha, part I. Retold by Ken and Visakha Kawasaki. Copyright @ 1995.