Surah Al-Isra' Ayah 96

Say: "Sufficient is Allah for a witness between me and you. Verily, He is Ever the All-Knower, the All-Seer of His servants. (96)

Allah tells His Prophet ﷺ 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 الْأَقَاوِيلِ - لَأَخَذْنَا مِنْهُ بِالْيَمِينِ - ثُمَّ لَقَطَعْنَا مِنْهُ الْوَتِينَ

(And 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 بَصِيرًا

(Verily, 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. He says: