وَإِن كُنتُمْ فِى رَيْبٍ مِّمَّا نَزَّلْنَا عَلَىٰ عَبْدِنَا فَأْتُوا۟ بِسُورَةٍ مِّن مِّثْلِهِۦ وَٱدْعُوا۟ شُهَدَآءَكُم مِّن دُونِ ٱللَّهِ إِن كُنتُمْ صَـٰدِقِينَ
wa-in kuntum fī raybin mimmā nazzalnā ʿalā ʿabdinā fatū bisūratin min mith'lihi wa-id'ʿū shuhadāakum min dūni l-lahi in kuntum ṣādiqīna
If you have doubts about the revelation We have sent down to Our servant, then produce a single sura like it- enlist whatever supporters you have other than God- if you truly [think you can].
And if you (Arab pagans, Jews, and Christians) are in doubt concerning that which We have sent down (i.e. the Qur’ân) to Our slave (Muhammad صلى الله عليه وسلم), then produce a Sûrah (chapter) of the like thereof and call your witnesses (supporters and helpers) besides Allâh, if you are truthful.