said that the Messenger of Allah (PBUH) said:
Our Lord (glorified and exalted be He) descends each night to the
earth's sky when there remains the final third of the night, and He
says: Who is saying a prayer to Me that I may answer it? Who is asking
somethingof Me that I may give it him? Who is asking forgiveness of Me
that I may forgive him?
It was related by al-Bukhari (also by Muslim, Malik, at-Tirmidhi and Abu Dawud).
In a version by Muslim the Hadith ends with the words:
And thus He continues till[the light of] dawn shines.
***
A poet wrote about this with the following couplet:
At every early dawn I hear this call:
the door of mercy is open, come one, come all.