The Prophet Sallallahu Alaihi Wasallam said,

Narrated Abu Musa Radiallahu anhu: The Prophet Sallallahu Alaihi Wasallam said, "Free the captives, feed the hungry and pay a visit to the sick."
{Sahih Bukhari, Book 52, No. 282}

Narrated Abu Huraira Radi Allahu Anhu The Prophet Sallallahu Alaihi Wasallam said, "If somebody manumits (free from slavery ) a Muslim slave, Allah will save from the Fire every part of his body for freeing the corresponding parts of the slave's body, even his private parts will be saved from the Fire) because of freeing the slave's private parts.
{Sahih Bukhari, book 79, 706}

Abu Huraira reported Allah's Messenger (may peace be upon him) as saying: Verily, Allah, the Exalted and Glorious, would say on the Day of Resurrection: O son of Adam, I was sick but you did not visit Me. He would say: O my Lord; how could I visit Thee whereas Thou art the Lord of the worlds? Thereupon He would say: Didn't you know that such and such servant of Mine was sick but you did not visit him and were you not aware of this that if you had visited him, you would have found Me by him? O son of Adam, I asked food from you but you did not feed Me. He would say: My Lord, how could I feed Thee whereas Thou art the Lord of the worlds? He said: Didn't you know that such and such servant of Mine asked food from you but you did not feed him, and were you not aware that if you had fed him you would have found him by My side? (The Lord would again say: ) O son of Adam, I asked drink from you but you did not provide Me. He would say: My Lord, how could I provide Thee whereas Thou art the Lord of the worlds? Thereupon He would say: Such and such of servant of Mine asked you for a drink but you did not provide him, and had you provided him drink you would have found him near Me.
{Sahih Muslim Book 032, Number 6232}