Do they then await (anything) other than the Hour, that it should come upon them ...

... suddenly? But some of its portents (indications and signs) have already come, and when it (actually) is on them, how can they benefit then by their reminder?
So know (O Muhammad SAW) that Lâ ilâha ill-allâh (none has the right to be worshipped but Allâh), and ask forgiveness for your sin, and also for (the sin of) believing men and believing women. And Allâh knows well your moving about, and your place of rest (in your homes).
Al Auran, Sura Mohammad.
Ayat - 18,19.