Word by Word Analysis

وَإِن كُنتُمْ فِى رَيْبٍ مِّمَّا نَزَّلْنَا عَلَىٰ عَبْدِنَا فَأْتُوا۟ بِسُورَةٍ مِّن مِّثْلِهِۦ وَٱدْعُوا۟ شُهَدَآءَكُم مِّن دُونِ ٱللَّهِ إِن كُنتُمْ صَـٰدِقِينَ 23

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.