وَإِن كُنتُمْ فِى رَيْبٍ مِّمَّا نَزَّلْنَا عَلَىٰ عَبْدِنَا فَأْتُوا۟ بِسُورَةٍ مِّن مِّثْلِهِۦ وَٱدْعُوا۟ شُهَدَآءَكُم مِّن دُونِ ٱللَّهِ إِن كُنتُمْ صَـٰدِقِينَ

And if you are in doubt about what We have sent down [i.e., the Qur’ān] upon Our Servant [i.e., Prophet Muḥammad (ﷺ)], then produce a sūrah the like thereof and call upon your witnesses [i.e., supporters] other than Allāh, if you should be truthful.

Al-Baqarah 23

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.

Al-An'am 24

فَلَمَّا جَنَّ عَلَيْهِ ٱلَّيْلُ رَءَا كَوْكَبًا ۖ قَالَ هَـٰذَا رَبِّى ۖ فَلَمَّآ أَفَلَ قَالَ لَآ أُحِبُّ ٱلْـَٔافِلِينَ

So when the night covered him [with darkness], he saw a star. He said, "This is my lord."1 But when it set, he said, "I like not those that set [i.e., disappear]."

Al-An'am 76

قُلْ يَـٰٓأَيُّهَا ٱلنَّاسُ إِن كُنتُمْ فِى شَكٍّ مِّن دِينِى فَلَآ أَعْبُدُ ٱلَّذِينَ تَعْبُدُونَ مِن دُونِ ٱللَّهِ وَلَـٰكِنْ أَعْبُدُ ٱللَّهَ ٱلَّذِى يَتَوَفَّىٰكُمْ ۖ وَأُمِرْتُ أَنْ أَكُونَ مِنَ ٱلْمُؤْمِنِينَ

Say, [O Muḥammad], "O people, if you are in doubt as to my religion - then I do not worship those which you worship besides Allāh; but I worship Allāh, who causes your death. And I have been commanded to be of the believers

Yunus 104

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