A Hajj pilgrim came to Medina and went to sleep in the Prophet’s Mosque. When he awoke he became suspicious that a bag containing one thousand dinars has been stolen from him. He looked here and there but could not find anyone. At that time, Imam Ja’far as-Sadiq (a.s) was praying in a corner. This man did not recognize him. He insisted that the Imam had stolen the bag. When the Imam asked him the man replied that it contained one thousand gold coins. Hearing this, the Imam came out of the Mosque to his residence and gave one thousand gold coins to this man. He took them and returned to his place, but he found his bag lying there.
He went back at once and seeking forgiveness tried to return those gold coins. The Imam said, “We have given what we gave and we would not take it back.” The man was astounded at the high morals and forgiveness of the Imam. He asked someone who that gentleman was. He was told that it is Imam Ja’far as-Sadiq (a.s). Hearing this he threw himself at the Imam’s feet and pleaded, “O son of the Messenger! Forgive my fault. I was in debt and this was the amount I was to repay to the creditor. That is why the imagination of its loss perturbed me.” The Imam said, “Go, I have forgiven you.”
Reference :Akhlaq al-A’imma, Morals & Manners of the Holy Imams