Sahih al-Bukhari 7494
Narrated Abu Huraira:
Allah's Messenger (ﷺ) 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)
حَدَّثَنَا إِسْمَاعِيلُ، حَدَّثَنِي مَالِكٌ، عَنِ ابْنِ شِهَابٍ، عَنْ أَبِي عَبْدِ اللَّهِ الأَغَرِّ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏
"‏ يَتَنَزَّلُ رَبُّنَا تَبَارَكَ وَتَعَالَى كُلَّ لَيْلَةٍ إِلَى السَّمَاءِ الدُّنْيَا حِينَ يَبْقَى ثُلُثُ اللَّيْلِ الآخِرُ فَيَقُولُ مَنْ يَدْعُونِي فَأَسْتَجِيبَ لَهُ، مَنْ يَسْأَلُنِي فَأُعْطِيَهُ، مَنْ يَسْتَغْفِرُنِي فَأَغْفِرَ لَهُ ‏"‏‏.‏