Angels Visit By Night & By Day

Hazrat Abu Hurairah رضي الله تعالیٰ عنه reported:

The Messenger of Allah صلى الله عليه و آله و صحبه و سلم said, "There are angels who take turns in visiting you by night and by day, and they all assemble at the dawn (Fajr) and the afternoon (`Asr) prayers. Those who have spent the night with you, ascend to the heaven and their Rubb, Who knows better about them, asks: `In what condition did you leave My slaves?' They reply: `We left them while they were performing Salat and we went to them while they were performing Salat."

~ Al-Bukhari and Muslim