Sahih Bukhari Volume 8, Book 80, Hadith 6323

حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ عَبْدِ اللَّهِ، حَدَّثَنَا مَالِكٌ، عَنِ ابْنِ شِهَابٍ، عَنْ أَبِي عَبْدِ اللَّهِ الأَغَرِّ، وَأَبِي، سَلَمَةَ بْنِ عَبْدِ الرَّحْمَنِ عَنْ أَبِي هُرَيْرَةَ ـ رضى الله عنه ـ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏"‏ يَتَنَزَّلُ رَبُّنَا تَبَارَكَ وَتَعَالَى كُلَّ لَيْلَةٍ إِلَى السَّمَاءِ الدُّنْيَا حِينَ يَبْقَى ثُلُثُ اللَّيْلِ الآخِرُ يَقُولُ مَنْ يَدْعُونِي فَأَسْتَجِيبَ لَهُ، مَنْ يَسْأَلُنِي فَأُعْطِيَهُ، وَمَنْ يَسْتَغْفِرُنِي فَأَغْفِرَ لَهُ ‏"‏‏

Narrated By Abu Huraira : Allah's Apostle said, "When it is the last third of the night, our Lord, the Blessed, the Superior, descends every night to the heaven of the world and says, 'Is there anyone who invokes Me (demand anything from Me), that I may respond to his invocation; Is there anyone who asks Me for something that I may give (it to) him; Is there anyone who asks My forgiveness that I may forgive him?'"