The Messenger of Allāh ﷺ said:
يَنْزِلُ رَبُّنَا تَبَارَكَ وَتَعَالَى كُلَّ لَيْلَةٍ إِلَى السَّمَاءِ الدُّنْيَا حِينَ يَبْقَى ثُلُثُ اللَّيْلِ الآخِرُ يَقُولُ مَنْ يَدْعُونِي فَأَسْتَجِيبَ لَهُ مَنْ يَسْأَلُنِي فَأُعْطِيَهُ مَنْ يَسْتَغْفِرُنِي فَأَغْفِرَ لَهُ
Our Rabb descends to the lowest heaven every last third of the night and says: “Who will supplicate to Me so that I may answer him? Who will ask of Me so that I may give him? Who will seek My forgiveness so that I may forgive him?”
— Narrated by Abū Hurayrah رضي الله عنه
Dalīl: Ṣaḥīḥ al-Bukhārī #1145, Ṣaḥīḥ Muslim #758, al-Adab al-Mufrad #753, al-Muwaṭṭaʾ #502, Sunan Abū Dāwūd #1315, Mishkāt al-Maṣābīḥ #1223, Jāmiʿ at-Tirmidhī #3498, Tamām al-Minnah P. 182, Irwā’ al-Ghalīl #450
Ḥukm: Muttafaqun Alayh, Ṣaḥīḥ to both Imām al-Bukhārī and Imām Muslim