The Bodhisatta was once a king’s chaplain. Before being hired, he had been educated by the best teachers at Taxila and he wondered if the king respected him more for his virtue or for his devotion to learning. To test this, he stole some coins in full view of the king’s treasurer.
He was taken before the king, and after being sentenced to death he said he was not a thief and explained why he had taken the coins. And being given this punishment showed that the king’s honor really was earned from his virtue, not his education. Forgiven for his crime, the Bodhisatta left the palace and lived out the rest of his life as an ascetic in the Himalayas.
In the Lifetime of the Buddha
One of the Buddha’s disciples had been a king’s chaplain before joining the brotherhood. He received more honor than anyone else in the king’s inner circle and wondered if it was because of his virtue or his devotion to learning, so he did the exact same test of his privilege. Forgiven by the king, the man became a disciple of the Buddha and eventually reached arahantship.
When the Buddha heard some other disciples discussing this, the Buddha told them this story so they knew that he himself had once done the same test in the past.
The Buddha did not identify any earlier births other than his own.