Hud - 11:13

أَمْ يَقُولُونَ افْتَرَاهُ قُلْ فَأْتُواْ بِعَشْرِ سُوَرٍ مِّثْلِهِ مُفْتَرَيَاتٍ وَادْعُواْ مَنِ اسْتَطَعْتُم مِّن دُونِ اللّهِ إِن كُنتُمْ صَادِقِينَ
[11:13]
Or, do they say: He has forged it. Say: Then bring ten forged chapters like it and call upon whom you can besides Allah, if you are truthful.
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!
Or they say: He hath invented it. Say: Then bring ten surahs, the like thereof, invented, and call on everyone ye can beside Allah, if ye are truthful!