أَمْ يَقُولُونَ ٱفْتَرَىٰهُ ۖ قُلْ فَأْتُوا۟ بِعَشْرِ سُوَرٍ مِّثْلِهِۦ مُفْتَرَيَـٰتٍ وَٱدْعُوا۟ مَنِ ٱسْتَطَعْتُم مِّن دُونِ ٱللَّهِ إِن كُنتُمْ صَـٰدِقِينَ ١٣
Or do they say, "He invented it"? Say, "Then bring ten sūrahs like it that have been invented and call upon [for assistance] whomever you can besides Allāh, if you should be truthful."