Verse Quran
15:99 And serve thy Lord until there come unto thee the Hour that is Certain.
74:47 "Until there came to us (the Hour) that is certain."
102:7 Again, ye shall see it with certainty of sight!

The Quran's Verse about certain

Jacop, beg, race, forbidden, age, old , late night prayer, on foot, fuss, recording, ya'uq, gog and magog, yaguth, break the oath, penance of vow, nuts, defeat, green, yathrib, food,