Ar-Ra'd (The Thunder)
Surah 13 · Verse 43
And those who do not believe say, “You are not a messenger.” Say, “Allah is sufficient as a Witness between me and you along with him with whom is the knowledge of the book.” (R 6)
Muhammed (PBH) does not need a certificate for his messenger ship from the infidels, Allah (SWT) and those who possess correct knowledge of Divine books are sufficient as witness.
