Al-An'am 6:114

Afaghayra Allahi abtaghee hakamanwahuwa allathee anzala ilaykumu alkitaba mufassalanwallatheena ataynahumu alkitabayaAAlamoona annahu munazzalun min rabbika bilhaqqifala takoonanna mina almumtareen

[Say], "Then is it other than Allāh I should seek as judge while it is He who has revealed to you the Book [i.e., the Qur’ān] explained in detail?" And those to whom We [previously] gave the Scripture know that it is sent down from your Lord in truth, so never be among the doubters.

So, should I seek someone other than Allah as judge, while it is He who has sent down to you the Book in details? Those We have given the Book know that it is revealed from your Lord with the truth. So, never be one of those who are in suspicion.