The Messenger of Allah (sal Allahu alaihi wa sallam) said: “He who cheats others is not one of us.” [Muslim]
Commentary: Several years ago a Muslim moved to London. He regularly took the bus to the Masjid in the downtown area. Some weeks after he arrived, he had taken the same bus. When he sat down, he discovered that the driver had accidentally given him too much change, a twopence extra.
As he considered what to do, he thought to himself, “You better give it back. It would be wrong to keep it.” Then he thought, “Oh, forget it, it's only a tuppence! Who would worry about this little amount? The bus company already charges too much; they’ll never miss it. Accept it as a gift from Allah.”
When his stop came, the Muslim paused momentarily at the door, then he handed the twopence back to the driver and said, “Here, you gave me too much change.” The (non-Muslim) driver replied, “I’ve been thinking lately of going to worship at your Mosque. I just wanted to see what you would do if I gave you too much change.”
When the man stepped off the bus his knees were weak and he had to grab the nearest light pole for support. He looked up to the heavens and cried, “Oh Allah, I almost sold You and Islam for two pennies!”
Shaykh Hamza Yusuf – Muhammad the Honest :http://www.halaltube.com/hamza-yusuf-muhammad-the-honest