﴿ يُدَبِّرُ ٱلْأَمْرَ مِنَ ٱلسَّمَآءِ إِلَى ٱلْأَرْضِ ثُمَّ يَعْرُجُ إِلَيْهِ فِى يَوْمٍۢ كَانَ مِقْدَارُهُۥٓ أَلْفَ سَنَةٍۢ مِّمَّا تَعُدُّونَ ﴾

“He governs all that exists, from the celestial space to the earth; and in the end all shall ascend unto Him [for judgment] on a Day the length whereof will be [like] a thousand years of your reckoning.”

He directs the command from the heaven to the earth for the duration of this world then it ascends then the command and the direction thereof returns to Him in a day whose measure is a thousand years by your reckoning in this world. In sūrat sa’ala An asker asked the measure is said to be ‘fifty thousand years’ Q. 704 — and this day is the Day of Resurrection reckoned so because of the severity of its terrors for the disbeliever. As for the believer however for him it will be easier than performing any one of his obligatory prayers in this world — as is stated in hadīth.