فَرَجَعُوا إِلَى أَنْفُسِهِمْ فَقَالُوا إِنَّكُمْ أَنْتُمُ الظَّالِمُونَ ﴿۶۴﴾ ثُمَّ نُكِسُوا عَلَى رُءُوسِهِمْ لَقَدْ عَلِمْتَ مَا هَؤُلَاءِ يَنْطِقُونَ ﴿۶۵﴾ قَالَ أَفَتَعْبُدُونَ مِنْ دُونِ اللَّهِ مَا لَا يَنْفَعُكُمْ شَيْئًا وَلَا يَضُرُّكُمْ ﴿۶۶﴾ أُفٍّ لَكُمْ وَلِمَا تَعْبُدُونَ مِنْ دُونِ اللَّهِ أَفَلَا تَعْقِلُونَ ﴿۶۷﴾ قَالُوا حَرِّقُوهُ وَانْصُرُوا آلِهَتَكُمْ إِنْ كُنْتُمْ فَاعِلِينَ ﴿۶۸﴾

﴾64﴿ Faraja'ooo ilaaa anfusihim faqaalooo innakum antumuz zaalimoon
﴾65﴿ Summa nukisoo 'alaa ru'oosihim laqad 'alimta maa haaa'ulaaa'i yantiqoon
﴾66﴿ Qaala afata'budoona min doonil laahi maa laa yanfa'ukum shai'anw wa laa yadurrukum
﴾67﴿ Uffil lakum wa limaa ta'budoona min doonil laah; afalaa ta'qiloon
﴾68﴿ Qaaloo harriqoohu wansurooo aalihatakum in kuntum faa'ileen

﴾64﴿ So they turned back to their own selves (reflecting) and said, "Indeed, you are the wrongdoers
﴾65﴿ Then they turned to their heads (in shame) and said, "Indeed, you know that these do not speak
﴾66﴿ Abraham (peace be upon him) said, Do you worship, besides Allah, that which does not benefit you in anything nor harm you
﴾67﴿ I detest you and what you worship besides Allah. Will you not then use reason
﴾68﴿ Qaaloo harriqoohu wansurooo aalihatakum in kuntum faa'ileen

[64] The meaning here is that they began to reflect and think deeply—like someone who is defeated in argument and realizes the strength of the opponent’s evidence—so they admitted their own wrongdoing.
This is because shirk is ẓulm (injustice).
Alternatively, their intended meaning of ẓālimūn (wrongdoers) may have been: You left these idols without guards; there was no one to protect them.
And the well-known saying applies here: “The one who cannot push away the axe from his own head—how will he protect his worshippers from hardship?”
[65] This refers to satanic influence and the lack of divine guidance (tawfīq) for faith—because even after recognizing the truth, they stood in opposition out of stubbornness and hostility.
Bowing their heads is a metaphor, either for opposition and defiance, or for feeling blame and shame, or for being struck with confusion and bewilderment.
[66] Since they admitted that these idols cannot speak, Ibrāhīm (peace be upon him) established the argument against them:
if they are incapable of speech, then they also cannot possess any power over benefit or harm.
Therefore, they are not worthy of worship.
[67] Uff is a word originally used upon seeing something filthy, and later came to be used in response to vile or false speech—expressing disgust, grief, or disavowal.
Here, it means: I disown you and your worship of those idols, except for Allah the Exalted.
Thus, this word expresses barā’ah (disavowal), not an insult to their deities.
Similar expressions of disavowal are found in Surah Az-Zukhruf (26) and Surah Al-Mumtaḥanah (4).
[68] When they were unable to present any proof, they turned to hostility instead. So, they consulted one another about killing or burning Ibrāhīm (peace be upon him)—as also mentioned in Surah Al-‘Ankabūt (29:24).
Eventually, they decided to burn him. They claimed this was to avenge their gods, saying that Ibrāhīm (peace be upon him) had dishonored them, so they must take revenge.
This shows the extreme foolishness of the polytheists—they considered their idols to be protectors, yet now believed they needed to defend and avenge them themselves.
In kuntum fā‘ilīn (if you are going to do anything) means: if you're going to act, then burning him is the only thing you should do.