Reward for Sadaqah (Hadith No. 1190)


Bismillah.
Narrated Abu Huraira
Allah's Apostle said, "If one gives in charity what equals one date-fruit from the honestly-earned money -- and Allah accepts only the honestly-earned money -- Allah takes it in His right (hand) and then enlarges its reward for that person (who has given it); as anyone of you brings up his baby horse, so much so that it becomes as big as a mountain."
Give little, earn lots (of reward). Condition: sincerity. No showing off. Purely for Allah's sake. (y)
Sadaqah comes from the word sidq (sincerity), i.e. it is a sign of sincerity of faith on the part of the person who gives it. Sadaqah means worshiping Allaah by giving money without that being made obligatory in sharee’ah (Islamic Law).

Virtues of Sadaqah

Allaah says (interpretation of the meaning): 
“O you who believe! Spend of that with which We have provided for you, before a Day comes when there will be no bargaining, nor friendship, nor intercession. And it is the disbelievers who are the Zaalimoon (wrongdoers)”
[al-Baqarah 2:254] 
And:
“The likeness of those who spend their wealth in the way of Allaah, is as the likeness of a grain (of corn); it grows seven ears, and each ear has a hundred grains. Allaah gives manifold increase to whom He wills. And Allaah is All-Sufficient for His creatures’ needs, All-Knower.
262. Those who spend their wealth in the Cause of Allaah, and do not follow up their gifts with reminders of their generosity or with injury, their reward is with their Lord. On them shall be no fear, nor shall they grieve”
[al-Baqarah 2:261-262] 
Further:
“O you who believe! Spend of the good things which you have (legally) earned, and of that which We have produced from the earth for you, and do not aim at that which is bad to spend from it, (though) you would not accept it save if you close your eyes and tolerate therein. And know that Allaah is Rich (Free of all needs), and Worthy of all praise”
[al-Baqarah 2:267] 
And:
“Believe in Allaah and His Messenger (Muhammad), and spend of that whereof He has made you trustees. And such of you as believe and spend (in Allaah’s way), theirs will be a great reward”
[al-Hadeed 57:7] 
It was narrated from Abu Hurayrah (may Allaah be pleased with him) that the Prophet (peace and blessings of Allaah be upon him) said: “There is no day on which the people get up but two angels come down and one of them says, ‘O Allaah, give in compensation to the one who spends (in charity),’ and the other says, ‘O Allaah, destroy the one who withholds.’”  
Narrated by al-Bukhaari, 1374; Muslim, 1010. 
It was narrated that Abu Sa’eed al-Khudri (may Allaah be pleased with him) said: The Messenger of Allaah (peace and blessings of Allaah be upon him) went out – on Eid al-Fitr or Eid al-Adha – to the prayer place, and when he had finished (the prayer) he preached to the people and enjoined them to give charity. He said, “O people, give in charity!” Then he went over to the women and said, “O women, give in charity for I have seen that you are the majority of the people of Hell.” When he went home, Zaynab the wife of Ibn Mas’ood came seeking permission to see him. It was said, “O Messenger of Allaah, here is Zaynab.” He said, “Which Zaynab?” It was said, “The wife of Ibn Mas’ood.” He said, “Yes, let her in.” So they let her in and she said, “O Prophet of Allaah, today you enjoined charity, and I have some jewelry which I wanted to give in charity, but Ibn Mas’ood claims that he and his child have more right to receive it in charity.” The Prophet (peace and blessings of Allaah be upon him) said: “Give it in charity to Ibn Mas’ood, for your husband and your child have the most right that you should give it to them in charity.” 
Narrated by al-Bukhaari, 1393; Muslim, 80. 
It was narrated from Abu Hurayrah (may Allaah be pleased with him) that the Messenger of Allaah (peace and blessings of Allaah be upon him) said: “Allaah said: ‘Spend, O son of Adam, and I shall spend on you.’” 
Narrated by al-Bukhaari, 5073; Muslim, 993. 
Find out the differences between Zakah and Sadaqah here.