أَمْ يَقُولُونَ افْتَرَاهُ قُلْ فَأْتُوا بِسُورَةٍ مِّثْلِهِ وَادْعُوا مَنِ اسْتَطَعْتُم مِّن دُونِ اللَّهِ إِن كُنتُمْ صَادِقِينَ

Do they say, ‘He has fabricated it?’ Say, ‘Then bring a surah like it, and invoke whomever you can, besides Allah, should you be truthful.’