Allah tells His Prophet:قُلْ كَفَى بِاللّهِ شَهِيدًا بَيْنِي وَبَيْنَكُمْSay:"Sufficient is Allah for a witness between me and you.Allah tells His Prophet how to prove that what he has brought is true, saying to him to tell them:"He (Allah) is a witness over me and over you. He knows what I have brought to you. If I were lying to you, He would take revenge on me in the severest manner," as Allah says:وَلَوْ تَقَوَّلَ عَلَيْنَا بَعْضَ الاٌّقَاوِيلِلاأَخَذْنَا مِنْهُ بِالْيَمِينِثُمَّ لَقَطَعْنَا مِنْهُ الْوَتِينَAnd if he had forged a false saying concerning Us, We surely would have seized him by his right hand, And then We certainly would have cut off his life artery. (69:44-46)Allah said;إِنَّهُ كَانَ بِعِبَادِهِ خَبِيرًا بَصِيرًاVerily, He is Ever the All-Knower, the All-Seer of His servants.meaning, He knows best who among them deserves blessings, good treatment and guidance, and who deserves to be doomed and led astray