Commentary of Verses 18 - 19
18. Do  they (who persist in unbelief and evil deeds) wait but for the Last  Hour – (waiting) that it come upon them all of a sudden? Now indeed its  portents have already come. But how can it benefit them to take  admonition when the Last Hour has (already) come upon them?
19. Then,  know (bear in mind) that there is no deity but God, and ask forgiveness  for your lapses, and for the believing men and believing women. God  knows from which (inner) state and (social) condition to which state and  condition you do and will move, and in which state and condition you  will be steady.