It was narrated from Abu Hurairah that the Messenger of Allah said: "Our Lord, the Blessed and Exalted, descends when one third of the night remains, every night, and He says: 'Who will ask of me. That I may give him? Who will call upon me? That I may answer him? Who will ask my forgiveness, that? I may forgive him?' until dawn comes." Hence they used to prefer voluntary prayers at the end of the night rather than at the beginning. (Sahih)