وَمِنْهُمْ أُمِّيُّونَ لَا يَعْلَمُونَ ٱلْكِتَـٰبَ إِلَّآ أَمَانِىَّ وَإِنْ هُمْ إِلَّا يَظُنُّونَ

And among them are unlettered ones who do not know the Scripture except [indulgement in] wishful thinking, but they are only assuming.

Al-Baqarah 78

سَيَقُولُ ٱلَّذِينَ أَشْرَكُوا۟ لَوْ شَآءَ ٱللَّهُ مَآ أَشْرَكْنَا وَلَآ ءَابَآؤُنَا وَلَا حَرَّمْنَا مِن شَىْءٍ ۚ كَذَٰلِكَ كَذَّبَ ٱلَّذِينَ مِن قَبْلِهِمْ حَتَّىٰ ذَاقُوا۟ بَأْسَنَا ۗ قُلْ هَلْ عِندَكُم مِّنْ عِلْمٍ فَتُخْرِجُوهُ لَنَآ ۖ إِن تَتَّبِعُونَ إِلَّا ٱلظَّنَّ وَإِنْ أَنتُمْ إِلَّا تَخْرُصُونَ

Those who associated [others] with Allāh will say, "If Allāh had willed, we would not have associated [anything] and neither would our fathers, nor would we have prohibited anything." Likewise did those before deny until they tasted Our punishment. Say, "Do you have any knowledge that you can produce for us? You follow not except assumption, and you are not but misjudging."

Al-An'am 148

وَإِن تُطِعْ أَكْثَرَ مَن فِى ٱلْأَرْضِ يُضِلُّوكَ عَن سَبِيلِ ٱللَّهِ ۚ إِن يَتَّبِعُونَ إِلَّا ٱلظَّنَّ وَإِنْ هُمْ إِلَّا يَخْرُصُونَ

And if you obey most of those upon the earth, they will mislead you from the way of Allāh. They follow not except assumption, and they are not but misjudging.1

Al-An'am 116

قُلْ هَلْ مِن شُرَكَآئِكُم مَّن يَهْدِىٓ إِلَى ٱلْحَقِّ ۚ قُلِ ٱللَّهُ يَهْدِى لِلْحَقِّ ۗ أَفَمَن يَهْدِىٓ إِلَى ٱلْحَقِّ أَحَقُّ أَن يُتَّبَعَ أَمَّن لَّا يَهِدِّىٓ إِلَّآ أَن يُهْدَىٰ ۖ فَمَا لَكُمْ كَيْفَ تَحْكُمُونَ

Say, "Are there of your 'partners' any who guides to the truth?" Say, "Allāh guides to the truth. So is He who guides to the truth more worthy to be followed or he who guides not unless he is guided? Then what is [wrong] with you - how do you judge?"

Yunus 35

وَذَٰلِكُمْ ظَنُّكُمُ ٱلَّذِى ظَنَنتُم بِرَبِّكُمْ أَرْدَىٰكُمْ فَأَصْبَحْتُم مِّنَ ٱلْخَـٰسِرِينَ

And that was your assumption which you assumed about your Lord. It has brought you to ruin, and you have become among the losers."

Fussilat 23