Sahih Muslim
The Book of Faith (Kitab Al-Iman)
Book Number: 001 / Hadith Number: 345
Abu Musa reported: The Messenger of Allah (znay peace be upon him) was standing amongst us and (he said) four (things): Verily Allah dock not sleep and it does not befit Him to sleep. He raises the scale and lowers it. The deeds of the day are presented to Him in the night and the deeds of the night in the day.