23وَإِن كُنتُمْ فِى رَيْبٍ مِّمَّا نَزَّلْنَا عَلَىٰ عَبْدِنَا فَأْتُوا۟ بِسُورَةٍ مِّن مِّثْلِهِۦ وَٱدْعُوا۟ شُهَدَآءَكُم مِّن دُونِ ٱللَّهِ إِن كُنتُمْ صَـٰدِقِينَ
24فَإِن لَّمْ تَفْعَلُوا۟ وَلَن تَفْعَلُوا۟ فَٱتَّقُوا۟ ٱلنَّارَ ٱلَّتِى وَقُودُهَا ٱلنَّاسُ وَٱلْحِجَارَةُ ۖ أُعِدَّتْ لِلْكَـٰفِرِينَ
[23-24] And if you be in doubt whether the Book We have sent down to Our Servant is from Us or not, then produce, at least, one Surah like this.24 You may call all your associates to assist you and avail yourselves of the help of any one other than Allah. If you are genuine in your doubt, do this. But if you do not do this, and you can never do this, then fear the Fire which has been prepared for the disbelievers and which shall have men and stones for fuel25
24This challenge had been given several times in the Qur'an at Makkah. It was meant to convince the opponents that the Qur'an is Divine Word and could not be produced by human mind. Now it was reiterated at Madinah. (See Yunus, X: 38-39, Hud XI: 13-14).Bani Israel XVII: 88, At Tur LII:33-34).
25The allusion means: "You alone will not become fuel for Hell, but the idols of stone which you worship as deities in the world, will also be there with you to show that they had no share whatever in Godhead."