Allah addressed His servant and Messenger Muhammad , saying:

[وَيَوْمَ نَبْعَثُ فِى كُلِّ أُمَّةٍ شَهِيدًا عَلَيْهِمْ مِّنْ أَنفُسِهِمْ وَجِئْنَا بِكَ شَهِيدًا عَلَى هَـؤُلآءِ]

(And on the Day when We resurrect a witness from each nation from among themselves, and We bring you (O Muhammad) as a witness against these.), meaning, your Ummah. The Ayah means: remember that Day and its terrors, and the great honor and high position that Allah has bestowed upon you. This Ayah is like the Ayah with which `Abdullah bin Mas`ud ended when he recited to the Messenger of Allah from the beginning of Surat An-Nisa'. When he reached the Ayah:

[فَكَيْفَ إِذَا جِئْنَا مِن كُلِّ أمَّةٍ بِشَهِيدٍ وَجِئْنَا بِكَ عَلَى هَـؤُلاءِ شَهِيداً ]

(How (will it be) then, when We bring from each nation a witness and We bring you (O Muhammad) as a witness against these) [4:41] the Messenger of Allah said to him:

«حَسْبُك»

(Enough.) Ibn Mas`ud said: "I turned to him and saw his eyes streaming with tears.''