The Buddha told this story at Jetavana about a conniving bhikkhu, who was the source of much trouble to other bhikkhus:

Long, long ago, when Brahmadatta was reigning in Baranasi, a shifty ascetic with long, matted hair, lived near a certain little village. The landowner had built a modest hermitage in the forest for him, and daily provided him with excellent food in his own house.

The landowner had a great fear of robbers and decided that the safest course to protect his money was to hide it in an unlikely place. Believing the matted-haired ascetic to be a model of sainthood, he brought a hundred pieces of gold to the hermitage, buried them there, and asked the ascetic to keep watch over the treasure.

"There's no need to say more, sir, to a man like me who has renounced the world. We hermits never covet what belongs to others."

"That's wonderful," said the landowner, who went off with complete confidence in the hermit's protestations.

As soon as the landowner was out of sight, the ascetic chuckled to himself, "Why, there's enough here to last a man his whole life!"

Allowing a few days to elapse, the hermit dug up the gold and reburied it conveniently by the road. The following morning, after a meal of rice and succulent curries at the landowner's house, the ascetic said, "My good sir, I've been staying here, supported by you, for a long time. Frankly, living so long in one place is like living in the world, which is forbidden to ascetics like me. I really cannot remain here any longer; the time has come for me to leave."

The landowner urged him to stay, but nothing could overcome the hermit's determination.

"Well, then," said the landowner, "if you must go, good luck to you." Reluctantly, he escorted the ascetic to the outskirts of the village and returned home.

After walking a short way by himself, the ascetic thought it would be a good thing to cajole the landowner. Sticking a straw in his matted hair, he hurried back to the village.

"What brings you back again?" asked the surprised landowner.

"I just noticed that a straw from your roof got stuck in my hair. We hermits must not take anything which has not been given to us, so I have brought it back to you."

"Throw it down, sir, and go your way," said the landowner. "Imagine!" he said to himself. "This ascetic is so honest he won't even take a straw which does not belong to him. What a rare person!" Thus, greatly impressed by the ascetic's honesty, the landowner bid him farewell again.

At that time the Bodhisatta, reborn as a merchant, was traveling to the border on business and happened to stop at that same little village, where he witnessed the ascetic's return with the piece of straw. Suspicion grew in his mind that the hermit must have robbed the landowner of something. He asked the rich man whether he had deposited anything in the ascetic's care.

"Yes," the landowner answered rather hesitantly, "a hundred pieces of gold."

"Well, why don't you just go and see if it's still safe?" the merchant suggested.

The landowner went to the deserted hermitage, dug where he had left his money, and found it gone. Rushing back to the merchant, he cried, "It's not there!"

"The thief is certainly that long-haired rascal of an ascetic," said the merchant. "Let's catch him."

The two men ran after the rogue and quickly caught him. They kicked him and beat him until he showed them where he had hidden the gold. After they had gotten back the money, the merchant looked at the coins and scornfully asked the ascetic, "Why didn't this hundred pieces of gold trouble your conscience as much as that straw? Take care, you hypocrite, never to play such a trick again!"

When his life ended, the merchant passed away to fare according to his desserts.

When he had ended his lesson, the Buddha said, "Thus you see, monks, that this monk was as conniving in the past as he is today." Then he identified the Birth by saying, "This monk was the scheming ascetic of those days, and I was the wise and good merchant."