Narrated Abu Dhar:
I asked the Prophet, "What is the best deed?" He replied, "To believe in Allah and to fight for His Cause." I then asked, "What is the best kind of manumission (of slaves)?" He replied, "The manumission of the most expensive slave and the most beloved by his master." I said, "If I cannot afford to do that?" He said, "Help the weak or do good for a person who cannot work for himself." I said, "If I cannot do that?" He said, "Refrain from harming others for this will be regarded as a charitable deed for your own good."
Abu Dharr reported: I said: Messenger of Allah, which of the deeds is the best? He (the Holy Prophet) replied: Belief in Allah and Jihad in His cause. I again asked: Who is the slave whose emancipation is the best? He (the Holy Prophet) replied: One who is valuable for his master and whose price is high. I said: If I can't afford to do it? He (the Holy Prophet) replied: Help an artisan or make anything for the unskilled (labourer). I (Abu Dharr) said: Messenger of Allah, you see that I am helpless in doing some of these deeds. He (the Holy Prophet) replied: Desist from doing mischief to the people. That is the charity of your person on your behalf.