Quran 13:43 Ar-Ra'd, ayah 43 of 43

وَيَقُولُ ٱلَّذِينَ كَفَرُوا۟ لَسْتَ مُرْسَلًا ۚ قُلْ كَفَىٰ بِٱللَّهِ شَهِيدًۢا بَيْنِى وَبَيْنَكُمْ وَمَنْ عِندَهُۥ عِلْمُ ٱلْكِتَـٰبِ ۝٤٣

13:43 They who disbelieve say: Thou art no messenger (of Allah). Say: Allah, and whosoever hath knowledge of the Scripture, is sufficient witness between me and you.