Musnad Ahmad Hadith 976

Abu Moosa al-Ash’ari visited al-Hasan bin `Ali bin Abi Talib (رضي الله عنه) when he was sick. `Ali (رضي الله عنه) said to him: Have you come to visit him because he is sick or is it a social visit? He said: No, rather I have come to visit him because he is sick, ‘Ali (رضي الله عنه) said: There is no Muslim who visits a sick person, but seventy thousand angels go out with him, all of them praying for forgiveness for him. If he went out in the morning [they continued to do that] until evening comes, and he will have a garden in Paradise. If he goes out in the evening, seventy thousand angels go out with him, all of them praying for forgiveness for him until morning comes, and he will have a garden in Paradise.”