Abu Hurairah reported,
The Prophet ﷺ said, "Our Lord 
descends every night when the first third of the night has passed and says, 'I am the King. Who is there asking of Me, that I may give him? Who is there calling upon Me, that I may answer him? Who is there seeking My forgiveness, that I may forgive him?' He continues in this way until dawn."
Ahmad 7792
Sahihحدثنا عبد الرزاق حدثنا معمر عن سهيل بن أبي صالح عن أبيه
عن أبي هريرة
عن النبي ﷺ قال ينزل ربنا عز وجل كل ليلة إذا مضى ثلث الليل الأول فيقول أنا الملك من ذا الذي يسألني فأعطيه من ذا الذي يدعوني فأستجيب له من ذا الذي يستغفرني فأغفر له فلا يزال كذلك إلى الفجر
Its isnad is sahih. Muslim related it (1:210), and Tirmidhi (no. 446, with our commentary) both of them from Qutayba bin Saeed, from Yaqub bin Abdul-Rahman Qari Iskandarani, from Suhayl, with this same isnad. The imam of imams, Ibn Khuzayma, also related it in Kitab al-Tawhid (p. 86) through Hisham bin Yusuf, from Muammar, from Suhayl. It has already been related through other lines from Abu Hurairah with similar wording, numbers 7500, 7582, 7611.His saying, "the first third of the night," with "first" in the nominative, describes the third. In the previous narrations it is stated as the last third, and for this reason the Hafiz labored in Fath al-Bari (3:26) to reconcile the various narrations.Tirmidhi said following his narration, "The hadith of Abu Hurairah is a hasan sahih hadith." This hadith has been related through many lines from Abu Hurairah from the Prophet ﷺ. It has also been related from him that he said, "Allah descends when the last third of the night remains," and this is the most sahih of the narrations, and this is the truth.