Sahih Muslim: Hadith 6494

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 You whereas You are 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 You whereas You are 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 You whereas You are 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.