Translation:

6. They have indeed rejected (the Message): so they will know soon (enough) the truth of what they mocked at!

Notes (Tafseer)

3141. They may laugh at Allah's Message of righteousness, but they will soon see the power of Truth and realise the real significance of the movement which they opposed. Where were the Pagans of Makkah after Badr, and still more, after the bloodless surrender of Makkah? And the meaning may be applied universally in all history.