﴿ لَّٰكِنِ ٱللَّهُ يَشْهَدُ بِمَآ أَنزَلَ إِلَيْكَ ۖ أَنزَلَهُۥ بِعِلْمِهِۦ ۖ وَٱلْمَلَٰٓئِكَةُ يَشْهَدُونَ ۚ وَكَفَىٰ بِٱللَّهِ شَهِيدًا ﴾

“However it be, God [Himself] bears witness to the truth of what He has bestowed from on high upon thee: out of His own wisdom has He bestowed it from on high, with the angels bearing witness thereto - although none can bear witness as God does.”

But God bears witness with what He has revealed to you; He has revealed it through His knowledge; and the angels also bear witness; and God suffices as a Witness. In mentioning His knowledge of [the Prophet's] sincerity God consoled him for the lies that created beings told about him. For this reason He said �God suffices as a Witness.�