http://www.buddhistdoor.com/OldWeb/reso ... tra.htm#31MASON WANTED
Once upon a time, a Brahman master indented to give a big party. He told his disciple, "I need earthenware for the party. Go to the market and fetch for me a mason."
On his way to the mason's home, the disciple came across a man whose donkey was loaded with earthenware for sale in the market. Yet all pottery was broken by the animal in the twinkling of an eye. On his return home, the man was crying and getting quite distraught. On seeing this, the disciple asked: "Why are you so sad and disappointed?"
The man replied, "I have been making earthenware with all my expedient means after toiling and moiling for many years. I was on my way to the market intending to sell them. But this dumb animal has broken all I had in no time. That's why I'm so distraught."
The disciple was glad to see and hear all this and said, "It's a good donkey. I should like to buy it."
The mason was delighted to sell it. When the disciple rode it back, the master asked, "Why didn't you come back with a mason? What's the idea of bringing a donkey here?"
The disciple replied, "This donkey is better than a mason, for it can break things in a split second what a mason has made over a long time."
The master said, "You are stupid and ignorant indeed. Although the donkey can break things in a second, it can't even make one pottery in a hundred years."
So are the people at large. Those who sometimes receive offerings from their benefactors for a hundred years, give nothing in return. On the contrary, they always do more harm than good.
This is held to be true with someone who shows ingratitude.