Bismillah Walhamdulillah Was Salaatu Was Salaam ‘ala Rasulillah Narrated Abu Dhar (Radi-Allahu ‘anhu):

The Prophet (Sallallahu ‘Alaihi Wa Sallam) asked me at sunset, “Do you know where the sun goes (at the time of sunset)?” I replied, “Allah and His Apostle know better.” He said, “It goes (i.e. travels) till it prostrates itself underneath the Throne and takes the permission to rise again, and it is permitted. A time will come when it will be about to prostrate itself but its prostration will not be accepted, and it will ask permission to go on its course but it will not be permitted, and it will be ordered to return from where it has come and so it will rise in the west. And that is the interpretation of the Statement of Allah: "And the sun runs its fixed course For a term (decreed). That is The Decree of (Allah) The Exalted in Might, The All-Knowing.” (36.38)

Bukhari Vol. 4 : No. 421