This [Qur’an] is notification for the people that they may be warned thereby and that they may know that He is but one God and that those of understanding will be reminded.
Ibrahim 52
Say, "What thing is greatest in testimony?"
Say, " Allah is witness between me and you. And this Qur'an was revealed to me that I may warn you thereby and whomever it reaches. Do you [truly] testify that with Allah there are other deities?"
Say, "I will not testify [with you]."
Say, "Indeed, He is but one God, and indeed, I am free of what you associate [with Him]."
Al-An'am 19