The Bodhisatta was once corn merchant. A snake-charmer used a trained monkey in his show and when he went to attend a festival, he left his monkey in the Bodhisatta’s care. The snake-charmer returned a week later and got his monkey, beating it with a bamboo stick right in the Bodhisatta’s shop.
Later, when the snake-charmer fell asleep, the monkey untied himself and climbed a mango tree. After eating a mango, the monkey dropped the mango seed on the snake-charmer’s head. The snake-charmer decided to recapture his monkey through sweet talk and told him that from now on he would treat him as though he were his own son. The monkey replied that because of getting beaten, he preferred to live in the forest and took off through the tree tops. The snake-charmer went home greatly upset.
In the Lifetime of the Buddha
The snake-charmer and monkey were earlier births of one of the Buddha’s elder disciples and a novice under his tutelage. The elder was very cruel to the novice, so he quit and went back home. The elder pleaded with the boy to return, promising to be kind. Eventually the boy agreed and became a novice again, but the elder’s behavior didn’t change. The boy quit again, and this time when the elder begged him to come back, the boy refused.
When the Buddha heard some disciples discussing this matter, he told them this story so they knew the elder was also cruel to the boy in the past.