If they fail to meet your challenge, then know that this is revealed with God’s knowledge, and that there is no god except He. Will you then submit?
فَإِلَّم يَستَجيبوا لَكُم فَاعلَموا أَنَّما أُنزِلَ بِعِلمِ اللَّهِ وَأَن لا إِلٰهَ إِلّا هُوَ فَهَل أَنتُم مُسلِمونَ
fa il lam yastajeeboo lakum fa’lamooo annamaaa unzilla bi’ilmil laahi wa al laaa ilaaha illaa Huwa fahal antum muslimoon