6:25
وَمِنْهُم مَّن يَسْتَمِعُ إِلَيْكَ ۖ وَجَعَلْنَا عَلَىٰ قُلُوبِهِمْ أَكِنَّةً أَن يَفْقَهُوهُ وَفِىٓ ءَاذَانِهِمْ وَقْرًا ۚ وَإِن يَرَوْا۟ كُلَّ ءَايَةٍ لَّا يُؤْمِنُوا۟ بِهَا ۚ حَتَّىٰٓ إِذَا جَآءُوكَ يُجَـٰدِلُونَكَ يَقُولُ ٱلَّذِينَ كَفَرُوٓا۟ إِنْ هَـٰذَآ إِلَّآ أَسَـٰطِيرُ ٱلْأَوَّلِينَ
And among them are those who listen to you, but We have placed over their hearts coverings, lest they understand it, and in their ears deafness. And if they should see every sign, they will not believe in it. Even when they come to you arguing with you, those who disbelieve say, "This is not but legends of the former peoples."
Context in Surah Al-An'am
Nearby ayahs help place verse 6:25 in sequence and meaning.
ثُمَّ لَمْ تَكُن فِتْنَتُهُمْ إِلَّآ أَن قَالُوا۟ وَٱللَّهِ رَبِّنَا مَا كُنَّا مُشْرِكِينَ
Then there will be no [excuse upon] examination except they will say, "By Allah, our Lord, we were not those who associated."
ٱنظُرْ كَيْفَ كَذَبُوا۟ عَلَىٰٓ أَنفُسِهِمْ ۚ وَضَلَّ عَنْهُم مَّا كَانُوا۟ يَفْتَرُونَ
See how they will lie about themselves. And lost from them will be what they used to invent.
وَهُمْ يَنْهَوْنَ عَنْهُ وَيَنْـَٔوْنَ عَنْهُ ۖ وَإِن يُهْلِكُونَ إِلَّآ أَنفُسَهُمْ وَمَا يَشْعُرُونَ
And they prevent [others] from him and are [themselves] remote from him. And they do not destroy except themselves, but they perceive [it] not.
وَلَوْ تَرَىٰٓ إِذْ وُقِفُوا۟ عَلَى ٱلنَّارِ فَقَالُوا۟ يَـٰلَيْتَنَا نُرَدُّ وَلَا نُكَذِّبَ بِـَٔايَـٰتِ رَبِّنَا وَنَكُونَ مِنَ ٱلْمُؤْمِنِينَ
If you could but see when they are made to stand before the Fire and will say, "Oh, would that we could be returned [to life on earth] and not deny the signs of our Lord and be among the believers."