It is narrated from Sayyiduna Abu Dharr (may Allah be pleased with him) that a man came to the Prophet (peace and blessings be upon him) and said: O Messenger of Allah! Which deed is best? He (peace and blessings be upon him) said: "Faith in Allah and striving (jihad) in His path." He said: Which slave is best to free? He (peace and blessings be upon him) said: "The one with the highest price and the most precious to its owners." He said: And if I am not able to? He (peace and blessings be upon him) said: "Help a weak person, or do work for someone who is unskilled." He said: And if I cannot do even that? Then he (peace and blessings be upon him) said: "Keep people safe from your evil; that too is a charity that you give to yourself."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الوصايا / 12595