Sahih Bukhari | Volume 9 | Hadith Number 586

Narrated by Abu Huraira
Allah's Apostle said, "Every night when it is the last third of the night, our Lord, the Superior, the Blessed, descends to the nearest heaven and says: Is there anyone to invoke Me that I may respond to his invocation? Is there anyone to ask Me so that I may grant him his request? Is there anyone asking My forgiveness so that I may forgive him?." (See Hadith No. 246,Vol. 2)