Sunan Ibn Majah, Chapter: The Book of the Sunnah

"The Messenger of Allah (saw) stood up amongst us and said five things. He said: 'Allah does not sleep, and it is not befitting that He should sleep. He lowers the Scales and raises them. The deed done during the day is taken up to Him before the deed done during the night, and the deed done during the night before the deed done during the day. His Veil is Light and if He were to remove it, the glory of His Face would burn everything of His creation, as far as His gaze reaches.'" (Sahih)