Sura Hūd 11:13

أَمْ يَقُولُونَ ٱفْتَرَىٰهُ قُلْ فَأْتُوا۟ بِعَشْرِ سُوَرٍ مِّثْلِهِۦ مُفْتَرَيَٰتٍ وَٱدْعُوا۟ مَنِ ٱسْتَطَعْتُم مِّن دُونِ ٱللَّـهِ إِن كُنتُمْ صَٰدِقِينَ

am yaqūlūna iftarāhu qul fa-ʾtū bi-ʿashri suwarin mithlihi muftarayātin wa-idʿū mani istaṭaʿtum min dūni allāhi in kuntum ṣādiqīna

Or they may say, "He forged it," Say, "Bring ye then ten suras forged, like unto it, and call (to your aid) whomsoever ye can, other than Allah!- If ye speak the truth!