HUUD — Ayat 14

فَإِن لَّمْ يَسْتَجِيبُواْ لَكُمْ فَاعْلَمُواْ أَنَّمَا أُنزِلِ بِعِلْمِ اللّهِ وَأَن لاَّ إِلَـهَ إِلاَّ هُوَ فَهَلْ أَنتُم مُّسْلِمُونَ

And if they do not respond to you - then know that the Qur'an was revealed with the knowledge of Allah and that there is no deity except Him. Then, would you [not] be Muslims?