Abu Hurairah reported,
The Messenger of Allah ﷺ said, "Allah descends to the lowest heaven every night when the first third of the night has passed and says, 'I am the King. Who is calling upon Me, that I may answer him? Who is asking of Me, that I may grant him? Who is seeking My forgiveness, that I may forgive him?' He continues like this until the dawn breaks."
Tirmidhi 446
Sahihحدثنا قتيبة حدثنا يعقوب بن عبد الرحمن الإسكندراني عن سهيل بن أبي صالح عن أبيه
عن أبي هريرة
أن رسول الله ﷺ قال ينزل الله إلى السماء الدنيا كل ليلة حين يمضي ثلث الليل الأول فيقول أنا الملك من ذا الذي يدعوني فأستجيب له من ذا الذي يسألني فأعطيه من ذا الذي يستغفرني فأغفر له فلا يزال كذلك حتى يضيء الفجر
to the lowest heaven every night to the lowest heaven every nightReference. Muslim also narrated it in the Book of the Prayer of Travellers, chapter on encouraging supplication and remembrance... etc, hadith 758, from Qutayba, with the same wording. It has another route that will come at 3498.Bukhari also narrated it, hadith 1145, from the hadith of Abu Hurairah, with the same wording.On this subject there are also narrations from Ali bin Abu Talib [Ahmad 1/120 and Darimi, hadith 191, 1493], Abu Saeed Khudri [Muslim, hadith 172/758], Rifa Juhani [Ibn Majah, hadith 1367], Jubayr bin Mutim [Ahmad 4/81, and Nasai in Kubra, hadith 10321, and Darimi, hadith 1488], Ibn Masud [Ahmad 1/388, 403, 446], Abu Darda [Daraqutni in his book Nuzul, pp. 151, 152, hadith 73, and Bazzar 4/83, hadith 3253], and Uthman bin Abu As [Ahmad 4/22, 117, 218, in abridged form].