﴿ وَإِن كُنتُمْ فِى رَيْبٍۢ مِّمَّا نَزَّلْنَا عَلَىٰ عَبْدِنَا فَأْتُوا۟ بِسُورَةٍۢ مِّن مِّثْلِهِۦ وَٱدْعُوا۟ شُهَدَآءَكُم مِّن دُونِ ٱللَّهِ إِن كُنتُمْ صَٰدِقِينَ ﴾

“And if you doubt any part of what We have, bestowed from on high, step by step, upon Our servant [Muhammad], then produce a surah of similar merit, and call upon any other than God to bear witness for you -if what you say is true!”

Please check ayah 2:24 for complete tafsir.