نَّحْنُ أَعْلَمُ بِمَا يَقُولُونَ وَمَا أَنتَ عَلَيْهِم بِجَبَّارٍ فَذَكِّرْ بِالْقُرْآنِ مَن يَخَافُ وَعِيدِ

We know well what they say, and you are not there to compel them. So admonish by the Quran those who fear My threat.