أُولَـيِكَ الَّذِينَ اشْتَرَوُاْ الضَّلَلَةَ بِالْهُدَى
...
Those are they who have purchased error for guidance.
Hence, they opposed the guidance, that is, not announcing the Prophet's description they find in their Books, the news about his prophecy and the good news of his coming which the previous Prophets proclaimed, as well as following and believing in him. Instead, they preferred misguidance by denying him, rejecting him and concealing his descriptions that were mentioned in their Books.
Allah said:
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وَالْعَذَابَ بِالْمَغْفِرَةِ
...
...and torment at the price of forgiveness,
meaning, they preferred torment over forgiveness due to the sins they have committed.
Allah then said:
...
فَمَأ أَصْبَرَهُمْ عَلَى النَّارِ
So how bold they are (for evil deeds which will push them) to the Fire.
Allah states that they will suffer such severe, painful torment that those who see them will be amazed at how they could bear the tremendous punishment, torture and pain that they will suffer.
We seek refuge with Allah from this evil end.
Allah's Statement: