Mishkat al-Masabih #1870

Abu Huraira reported God's messenger as saying, "When the first night of Ramadan comes the devils and the rebellious jinn are chained, the gates of hell are locked and not one of them is opened; the gates of paradise are opened and not one of them is locked, and a crier calls, 'You who desire what is good, come forward, and you who desire evil refrain.' Some are freed from hell by God, and that happens every night." Tirmidhi and Ibn Majah transmitted it, and Ahmad transmitted it from a man. Tirmidhi said this is a gharib tradition.