Sayyiduna Anas (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: "A man from the people of Paradise will look down upon the people of Hell, and a man from the people of Hell will call out to him: 'O so-and-so, do you recognise me?' The man of Paradise will say: 'No, by Allah, I do not recognise you. Who are you? Woe to you!' He will say: 'I am the man who passed by you in the world, and you asked me for water to drink and I gave you a drink; because of that, intercede for me before your Lord!' The Prophet (peace and blessings be upon him) said: That (man of Paradise) will present himself before his Lord, where other people will also be present, and will say: 'O Lord, I looked down upon the people of Hell, and a man from the people of Hell stood up and called out: "O so-and-so, do you not recognise me?" I said: "No, by Allah, I did not recognise you. Who are you?" He said: "I am the man by whom you passed in the world, and you asked me for a drink and I gave you a drink, so now because of that intercede for me before your Lord." So, O my Lord, accept my intercession for him!' The Prophet (peace and blessings be upon him) said: Then Allah Almighty will accept his (the man of Paradise's) intercession for him (the man of Hell) and will bring him out of Hell."
Abu Ya'la recorded it; its chain contains a narrator, Abu Ali bin Abi Sarah, and he is matruk (abandoned).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب البعث / 18550