Sura Yūnus 10:38

أَمْ يَقُولُونَ ٱفْتَرَىٰهُ قُلْ فَأْتُوا۟ بِسُورَةٍ مِّثْلِهِۦ وَٱدْعُوا۟ مَنِ ٱسْتَطَعْتُم مِّن دُونِ ٱللَّـهِ إِن كُنتُمْ صَٰدِقِينَ

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

Or do they say, "He forged it"? say: "Bring then a Sura like unto it, and call (to your aid) anyone you can besides Allah, if it be ye speak the truth!"