It was narrated that a poor man knocked on the door of a scholar at night asking for charity. The scholar asked his wife what food they have, and she said: We only have 10 eggs. He said: Give them to him. She gave him the eggs except one, she kept it for her children. After some time, a man knocked on the door and gave the scholar ninety dinars. The scholar asked his wife how much she gave to the poor man. She said: Nine eggs. He said: These are ninety dinars and one good deed is rewarded (by Allah) with ten the like of it.
Men Aja'ib al-Sadaqah (The Wonders of Giving Charity) By Khalid bin Suliman al-Rabai'