The Jataka story of the Poisonous Nimb Tree.
Once upon the time, the Bodhisattva came to life as a young man from a good family in the North country. He went to Takasila for his education and other training and accomplished all his studies. Then, he returned to his city to work and eventually became a recluse after his parents had passed away. Taking a hermitage in the Himalayas, he practiced meditation and attained profound wisdom and knowledge. Before settling down for a Summer retreat, he went to Banares to get salt and other things for living. When he was getting his necessities on the streets of the city, the king saw him while looking out from a window of his palace. Impressed by his dignity in his walking manner and his lion-like majesty, the king sent one of his courtiers to find out who that hermit was. Knowing that the recluse was seeking to settle for his summer retreat, the king happily invited him to stay as a guest in the city. The king built a hermitage in his royal garden for the recluse to live and had his gardeners to serve him. Two or three times a day, the king made his visit to the garden to meet the recluse.
One day, the king came and talked to the hermit about his son, a young prince who was cruel and fierce. The king and his counselors had tried to teach the prince to follow a more compassionate and peaceful manners, but all were in vain. The young prince did not pay any attention to their advice. He went on irritating others with his unkind commands and bitter words. In this visit, the king hoped that the wise and virtuous hermit would be able to set his son in a righteous path suitable for his royal duties. The hermit agreed to help and requested the king to bring the young prince to the garden.
The hermit took the young price out for a walk when he came to the royal garden. Beautiful flowers of many colors were in full bloom along the path. Here and there young plants were growing on the soil around the big shady trees. As a habit, the you prince wanted to uproot those plants that he did not like. The wise hermit encouraged the price to walk on for a view of other better plants till they came to a seedling Nimb tree. Having grown for only a few days, the tiny plant had only two leaves, one on one side, and one on the other.
"Taste a leave of this little plant, Dear Prince," said the hermit, "and see what it is like."
The young prince did so; but scarcely had he put the leaf in his mouth, when he spat out with an oath, and hawked and spat to get the taste out of his mouth.
"What is the matter, Dear Prince?" asked the hermit.
"Sir, today this tree only suggests a deadly poison; but if left to grow, it will prove the death to many persons," said the enraged young prince, as he rushed forward, plucked up, and crushed in his hands the tiny plant, reciting these lines:
If poison lurk in the baby tree,
What will the full growth prove to be?
Then the hermit said to him, "Prince, dreading what the poisonous seedling might grow to, you have torn it up into pieces. Similarly, as you acted to the tree, so the people of this kingdom, dreading what a price as fierce and cruel may become king, will not place you on the throne but uproot you like this Nimb tree and drive you forth to exile. Therefore take warning by the tree and show compassion and spread loving-kindness."
From that moment on, the mood of the prince was changed. He grew humble and meek, compassionate and overflowing with kindness. Abiding by the counsel of the wise hermit, when he became king after his father's death, he abounded in compassionate charity and other good works, and in the end passed away to fare according to his good deeds.
The Buddha told the the story about the Poisonous Nimb Tree while residing at Vaisali to tame one of the king's sons, known as Prince Wicked Licchavi Prince , a fierce, passionate and cruel young man, always punishing, like an enraged viper, and ended his discourse by identifying Ananda as the king and the hermit as the Master himself.
*Drawn from the Ekapanna Jataka, No. 149.