as He, exalted is He, said:

“If he had dared to attribute to Us even a few statements, (44)
We would surely have seized him by the right hand, (45)
then severed his very lifeline, (46)
and none of you could have protected him.” (47)
[al-Ḥāqqah 44–47]

“Or do they say, ‘He has fabricated a lie about Allah’? If Allah so willed, He could seal your heart. Allah wipes out falsehood and proves the truth by His words.”
[ash-Shūrā 24]

And He, exalted be He, also said:

“When We substitute one verse in place of another—and Allah knows best what He sends down—they say, ‘You are only a forger.’ Yet most of them do not know. (101)
Say: The Holy Spirit has brought it down from your Lord in truth, to make firm those who believe, and as guidance and glad tidings for the Muslims.”
[an-Naḥl 101–102]

And He, exalted is He, said:

“When Our clear revelations are recited to them, those who do not look forward to meeting Us say, ‘Bring a Qur’an other than this, or change it.’ Say: It is not for me to change it of my own accord; I follow only what is revealed to me. Indeed, were I to disobey my Lord, I would fear the torment of a momentous Day. (15)
Say: Had Allah so willed, I would not have recited it to you, nor would He have made it known to you. I have already spent a lifetime among you before this—will you not use your reason?” (16)
[Yūnus 15–16]

Accordingly, if even a single word of this Book were a lie against Allah, it would cease to be the Book of Allah, and it could not have been brought by the Messenger of Allah—for a liar may well speak truth in most of what he says