Translation:

8. If We delay the Penalty for them for a definite term they are sure to say "What keeps it back?" Ah! on the day it (actually) reaches them nothing will turn it away from them and they will be completely encircled by that which they used to mock at!

Notes (Tafseer)

1505. As much as to say: "Oh! all this talk of punishment is nonsense. There is no such thing!"