Surah Yunus (Jonah), Verse 38

اَمْ یَقُوْلُوْنَ افْتَرٰىهُ قُلْ فَاْتُوْا بِسُوْرَةٍ مِّثْلِهٖ وَادْعُوْا مَنِ اسْتَطَعْتُمْ مِّنْ دُوْنِ اللّٰهِ اِنْ كُنْتُمْ صٰدِقِیْنَ ۟

Am yaqooloonaf taraahu qul fa'too bi sooratin mislihee wad'oo manis tata'tum min doonil laahi in kuntum saadiqeen

“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!"”

Quran 10:38 (Yusuf Ali Translation)