The Bodhisatta was once a tree fairy. A lion and a tiger lived together in a cave, and they let a jackal eat their leftover meat. The jackal had never eaten lion or tiger meat and wanted very much to do so. He knew that if he got the two friends arguing they would kill each other, and he would get his special meals.
The jackal told the lion that the tiger spoke poorly of him, saying the lion was not even one-sixteenth as beautiful or strong as he was. The lion sent the jackal away, saying the tiger would never say such things. Then the jackal told the tiger the same lie about the lion. The tiger asked his friend if it was true, and the lion denied it. The tiger apologized for doubting him, and the lion forgave him. The two remained close friends, and the jackal fled. The Bodhisatta saw all this happen.
In the Lifetime of the Buddha
The lion and tiger were earlier births of Sariputta and Moggallana, two of the Buddha’s top disciples. They spent a rainy season living in the wilderness, and a beggar (the jackal was an earlier birth of him) who lived nearby assisted them in exchange for leftover food. The two elders were close friends, and when the beggar saw how harmoniously they lived, he wanted to make them quarrel. He told Sariputta that Moggallana spoke poorly of him, claiming he was lower in both lineage and spiritual attainments. Sariputta knew the beggar was lying and thought nothing of it. Then the beggar told Moggallana the same story, and he also rejected it. The elders sent the beggar away.
When they returned to the Buddha’s monastery, Sariputta and Moggallana told him about their experience with the beggar, and the Buddha told them this story so they knew that he had done the same thing to them in the past.