The Day when We will fold the heaven like the folding of a [written] sheet for the records. As We began the first creation, We will repeat it. [That is] a promise binding upon Us. Indeed, We will do it.1
Translation: Saheeh International (English)
1 More literally, "Indeed, We are ever doers" of what We will.
On the day in which I shall roll up the heavens like the rolling up of a scroll, and congregate the creation in the state they were created in the first instance. I have promised that it will happen; a promise that there is no going back on. I shall indeed fulfil My promise.