Sunan Ibn Majah, Chapter: The Chapters of Establishing the Prayer and the Sunnah Regarding Them

"The Messenger of Allah (saw) said: 'When it is the night of the middle of Sha'ban, spend its night in prayer and observe a fast on that day. For Allah descends at sunset on that night to the lowest heaven and says: 'Is there no one who will ask Me for forgiveness, that I may forgive him? Is there no one who will ask Me for provision, that I may provide for him? Is there no one who is afflicted by trouble, that I may relieve him?' And so on, until dawn comes.'" Daif