The Prophet's Universal Prophethood and Witnessing Role

وَيَوْمَ نَبْعَثُ فِى كُلِّ أُمَّةٍ شَهِيدًا عَلَيْهِم مِّنْ أَنفُسِهِمْ ۖ وَجِئْنَا بِكَ شَهِيدًا عَلَىٰ هَـٰٓؤُلَآءِ ۚ وَنَزَّلْنَا عَلَيْكَ ٱلْكِتَـٰبَ تِبْيَـٰنًا لِّكُلِّ شَىْءٍ وَهُدًى وَرَحْمَةً وَبُشْرَىٰ لِلْمُسْلِمِينَ

And [mention] the Day when We will resurrect among every nation a witness over them from themselves [i.e., their prophet]. And We will bring you, [O Muḥammad], as a witness over these [i.e., your nation]. And We have sent down to you the Book as clarification for all things and as guidance and mercy and good tidings for the Muslims.