The Spider - 29:52
"Say, "Allah is sufficient as a witness between me and you. He knows whatever is in the heavens and the earth. Those who believe in falsehood and do not believe in Allah are the losers."
Allah is a witness to the messengership of Prophet Muhammad against the rejection of the people of the Book:
The Thunder/13:43
"Those who disbelieve say, "You are not a messenger!"Say, "Allah and those who have the knowledge of the Book are sufficient as witnesses between me and you."
The Cattle/6:19
"Ask: "Whose testimony is the greatest?"Say: "Allah is the witness between me and you. I have been given this Qur´an to warn you and all those to whom it reaches. Do you bear witness that there is another god besides Allah?"Say: "I do not bear witness to that,"and then say: "He is the only God, and I am far from that which you associate partners with."
The Spider/29:50
"They said, "Should not a miracle have descended to him from your Lord?"Say, "Miracles are with Allah. I am only a clear warner."
The Spider/29:51
Is it not enough for them that We have sent down this Book to you and it has been read to them? In that is a mercy and an admonition for a people who believe.
The Spider/29:52
"Say, "Allah is sufficient as a witness between me and you. He knows whatever is in the heavens and the earth. Those who believe in falsehood and do not believe in Allah are the losers."
The Night Journey/17:94
"When Hidayet came to them, the people said: "Has Allah sent a human being as a messenger?"
The Night Journey/17:95
"Say: "If there were angels inhabiting the earth, We would have sent to them an angel from heaven as a messenger."
The Night Journey/17:96
"Say: "Allah is a witness between me and you. He hears from His servants and sees."
The Sandhills/46:8
"Or do they say, "He fabricated it"? Say, "If I have fabricated it, you cannot protect me against anything from Allah. He knows best your transgression. He is sufficient as a witness between me and you. He is Forgiving, Merciful."